zh-TW: Update english message from latest source (#758)

Auto-generated from the following commands:

```
MDBOOK_OUTPUT='{"xgettext": {"pot-file": "messages.pot"}}' \
mdbook build -d po
msgmerge --update po/zh-TW.po po/messages.pot
```

po/zh-TW.po

@@ -5,10 +5,10 @@ msgstr ""
 "PO-Revision-Date: 2023-06-01 22:43+0800\n"
 "Last-Translator: Hank Chen <kuanhungchen@google.com>\n"
 "Language-Team: Traditional Chinese (Taiwan) <zh-l10n@lists.linux.org.tw>\n"
+"Language: zh-TW\n"
 "MIME-Version: 1.0\n"
 "Content-Type: text/plain; charset=UTF-8\n"
 "Content-Transfer-Encoding: 8bit\n"
-"Language: zh-TW\n"
 "Plural-Forms: nplurals=1; plural=0;\n"
 
 #: src/SUMMARY.md:3
@@ -1148,7 +1148,7 @@ msgstr ""
 #: src/ownership/lifetimes-data-structures.md:23
 #: src/exercises/day-1/afternoon.md:9 src/exercises/day-1/book-library.md:100
 #: src/structs.md:29 src/structs/tuple-structs.md:35
-#: src/structs/field-shorthand.md:25 src/enums.md:31
+#: src/structs/field-shorthand.md:25 src/enums.md:32
 #: src/enums/variant-payloads.md:33 src/enums/sizes.md:27 src/methods.md:28
 #: src/methods/receiver.md:22 src/methods/example.md:44
 #: src/pattern-matching.md:23 src/pattern-matching/destructuring-enums.md:33
@@ -1254,7 +1254,7 @@ msgstr ""
 #: src/ownership/lifetimes-data-structures.md:30
 #: src/exercises/day-1/afternoon.md:15 src/exercises/day-1/book-library.md:104
 #: src/structs.md:42 src/structs/tuple-structs.md:43
-#: src/structs/field-shorthand.md:72 src/enums.md:41
+#: src/structs/field-shorthand.md:72 src/enums.md:42
 #: src/enums/variant-payloads.md:45 src/enums/sizes.md:155 src/methods.md:41
 #: src/methods/receiver.md:28 src/methods/example.md:53
 #: src/pattern-matching.md:35 src/pattern-matching/destructuring-enums.md:39
@@ -1277,7 +1277,7 @@ msgstr ""
 #: src/traits/trait-bounds.md:50 src/traits/impl-trait.md:44
 #: src/traits/iterator.md:42 src/traits/from-iterator.md:26
 #: src/traits/from-into.md:33 src/traits/drop.md:42 src/traits/default.md:47
-#: src/traits/operators.md:38 src/traits/closures.md:38
+#: src/traits/operators.md:40 src/traits/closures.md:38
 #: src/exercises/day-3/morning.md:11 src/error-handling/result.md:33
 #: src/error-handling/try-operator.md:53
 #: src/error-handling/converting-error-types-example.md:60
@@ -1574,6 +1574,23 @@ msgid ""
 msgstr ""
 
 #: src/running-the-course/translations.md:11
+msgid "## Incomplete Translations"
+msgstr ""
+
+#: src/running-the-course/translations.md:13
+msgid ""
+"There is a large number of in-progress translations. We link to the most\n"
+"recently updated translations:"
+msgstr ""
+
+#: src/running-the-course/translations.md:16
+msgid ""
+"* [French][fr] by [@KookaS] and [@vcaen].\n"
+"* [German][de] by [@Throvn] and [@ronaldfw].\n"
+"* [Japanese][ja] by [@CoinEZ-JPN] and [@momotaro1105]."
+msgstr ""
+
+#: src/running-the-course/translations.md:20
 msgid ""
 "If you want to help with this effort, please see [our instructions] for how "
 "to\n"
@@ -1920,11 +1937,12 @@ msgid ""
 "encouraged!\n"
 "  * As an instructor, you should try to keep the discussions relevant, i."
 "e.,\n"
-"    keep the related to how Rust does things vs some other language. It can "
-"be\n"
-"    hard to find the right balance, but err on the side of allowing "
-"discussions\n"
-"    since they engage people much more than one-way communication.\n"
+"    keep the discussions related to how Rust does things vs some other "
+"language. \n"
+"    It can be hard to find the right balance, but err on the side of "
+"allowing \n"
+"    discussions since they engage people much more than one-way "
+"communication.\n"
 "* The questions will likely mean that we talk about things ahead of the "
 "slides.\n"
 "  * This is perfectly okay! Repetition is an important part of learning. "
@@ -2188,7 +2206,7 @@ msgstr ""
 
 #: src/why-rust/compile-time.md:19
 msgid ""
-"* You can for use [`Box::leak`] to leak a pointer. A use of this could\n"
+"* You can use [`Box::leak`] to leak a pointer. A use of this could\n"
 "  be to get runtime-initialized and runtime-sized static variables\n"
 "* You can use [`std::mem::forget`] to make the compiler \"forget\" about\n"
 "  a value (meaning the destructor is never run).\n"
@@ -4205,7 +4223,7 @@ msgid ""
 "    a valid solution.\n"
 "* Lifetimes for function arguments and return values must be fully "
 "specified,\n"
-"  but Rust allows these to be elidied in most cases with [a few simple\n"
+"  but Rust allows these to be elided in most cases with [a few simple\n"
 "  rules](https://doc.rust-lang.org/nomicon/lifetime-elision.html)."
 msgstr ""
 
@@ -4249,7 +4267,7 @@ msgstr ""
 
 #: src/ownership/lifetimes-function-calls.md:31
 msgid ""
-"* Move the declaration of `p2` and `p3` into a a new scope (`{ ... }`), "
+"* Move the declaration of `p2` and `p3` into a new scope (`{ ... }`), "
 "resulting in the following code:\n"
 "  ```rust,ignore\n"
 "  #[derive(Debug)]\n"
@@ -4280,7 +4298,7 @@ msgid ""
 "    another reference.\n"
 "  * It must have come from one of those two inputs (or from a global "
 "variable).\n"
-"  * Which one is it? The compiler needs to to know, so at the call site the "
+"  * Which one is it? The compiler needs to know, so at the call site the "
 "returned reference is not used\n"
 "    for longer than a variable from where the reference came from."
 msgstr ""
@@ -4709,7 +4727,7 @@ msgid ""
 "```"
 msgstr ""
 
-#: src/structs.md:31 src/enums.md:33 src/enums/sizes.md:29 src/methods.md:30
+#: src/structs.md:31 src/enums.md:34 src/enums/sizes.md:29 src/methods.md:30
 #: src/methods/example.md:46 src/pattern-matching.md:25
 #: src/pattern-matching/match-guards.md:22 src/control-flow/blocks.md:42
 msgid "Key Points:"
@@ -4892,6 +4910,7 @@ msgstr ""
 msgid ""
 "```rust,editable\n"
 "fn generate_random_number() -> i32 {\n"
+"    // Implementation based on https://xkcd.com/221/\n"
 "    4  // Chosen by fair dice roll. Guaranteed to be random.\n"
 "}\n"
 "\n"
@@ -4916,7 +4935,7 @@ msgid ""
 "```"
 msgstr ""
 
-#: src/enums.md:35
+#: src/enums.md:36
 msgid ""
 "* Enumerations allow you to collect a set of values under one type\n"
 "* This page offers an enum type `CoinFlip` with two variants `Heads` and "
@@ -8079,7 +8098,7 @@ msgid "# The `Default` Trait"
 msgstr ""
 
 #: src/traits/default.md:3
-msgid "[`Default`][1] trait provides a default implementation of a trait."
+msgid "[`Default`][1] trait produces a default value for a type."
 msgstr ""
 
 #: src/traits/default.md:5
@@ -8172,11 +8191,15 @@ msgid ""
 "        the operator for `&T` as well. This avoids unnecessary cloning on "
 "the\n"
 "        call site.\n"
-"* Why is `Output` an associated type? Could it be made a type parameter?\n"
-"    * Short answer: Type parameters are controlled by the caller, but\n"
+"* Why is `Output` an associated type? Could it be made a type parameter of "
+"the method?\n"
+"    * Short answer: Function type parameters are controlled by the caller, "
+"but\n"
 "        associated types (like `Output`) are controlled by the implementor "
 "of a\n"
-"        trait."
+"        trait.\n"
+"* You could implement `Add` for two different types, e.g.\n"
+"  `impl Add<(i32, i32)> for Point` would add a tuple to a `Point`."
 msgstr ""
 
 #: src/traits/closures.md:1