Allow to overwrite the response Content-Type from options (#1134)

* Allow to override the response `Content-Type` from options

* Apply suggestions from code review

Co-authored-by: Jakub Roztocil <jakub@roztocil.co>

* Rename the option from `--response.content-type` to `--response-as`

* Update CHANGELOG.md

Co-authored-by: Jakub Roztocil <jakub@roztocil.co>

docs/README.md

@@ -1214,14 +1214,15 @@ You can further control the applied formatting via the more granular [format opt
 
 This is something you will typically store as one of the default options in your [config](#config) file.
 
-
-Binary data is suppressed for terminal output, which makes it safe to perform requests to URLs that send back binary data.
-Binary data is also suppressed in redirected but prettified output.
-The connection is closed as soon as we know that the response body is binary,
-
-```bash
-$ http pie.dev/bytes/2000
-```
+#### Response `Content-Type`
+
+The `--response-as=value` option is a shortcut for `--format-options response.as:value`,
+and it allows you to override the response `Content-Type` sent by the server.
+That makes it possible for HTTPie to pretty-print the response even when the server specifies the type incorrectly.
+
+For example, the following request will force the response to be treated as XML:
+
+```bash
 $ http --response-as=application/xml pie.dev/get
 ```
 
@@ -1236,6 +1237,18 @@ sorting-related format options (currently it means JSON keys and headers):
 ```
 
 You will nearly instantly see something like this:
+
+```http
+HTTP/1.1 200 OK
+Content-Type: application/octet-stream
+
+```
+
+### Redirected output
+
+HTTPie uses a different set of defaults for redirected output than for [terminal output](#terminal-output).
+The differences being:
+
 - Formatting and colors aren’t applied (unless `--pretty` is specified).
 - Only the response body is printed (unless one of the [output options](#output-options) is set).
 - Also, binary data isn’t suppressed.