docstring update: add see also section.

jc/parsers/semver.py

@@ -2,6 +2,8 @@
 
 This parser conforms to the specification at https://semver.org/
 
+See also: `ver` parser.
+
 Usage (cli):
 
     $ echo 1.2.3-rc.1+44837 | jc --semver

jc/parsers/ver.py

@@ -12,6 +12,8 @@ All other version strings will have a `strict` value of `false` and a
 `components` key will contain a list of detected parts of the version
 string.
 
+See Also: `semver` parser.
+
 Usage (cli):
 
     $ echo '1.2b' | jc --ver