docs: update contributing + FAQ docs for gst-indent

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/5192>

subprojects/gst-docs/markdown/contribute/index.md

@@ -426,25 +426,21 @@ In the simplest case, you might be able to get away with just doing a `git pull
 
 #### Coding Style
 
-Try to stick to the GStreamer indentation and coding style. There is a script
+Try to stick to the GStreamer indentation and coding style. There is an
-called [`gst-indent`][gst-indent] which you can run over your `.c` or `.cpp`
+application called [`gst-indent`][gst-indent] which should be available
-files if you want your code auto-indented before making the patch. The script
+in a GStreamer development environment and which you can run over your `.c` or
-requires GNU indent to be installed already. Please do _not_ run `gst-indent` on
+`.cpp` files if you want your code auto-indented before making the patch.
-header files, our header file indentation is free-form. If you build GStreamer
-from git, a local commit hook will be installed that checks if your commit
-conforms to the required style (also using GNU indent).
 
-Different versions of GNU indent may occasionally yield slightly different
+Please do _not_ run `gst-indent` on header files, our header file
-indentations. If that happens, please ignore any indentation changes in
+indentation is free-form.
-sections of code that your patch does not touch. You can do that by staging
+
-changes selectively via `git add -p`. You can bypass the local indentation
+If you build GStreamer from git, a local commit hook will be installed that
-check hook by using `git commit -n`, but it will still be checked again later
+checks if your commit conforms to the required style. You can bypass that local
-when you submit your changes through GitLab for merging.
+indentation check hook by using `git commit -n`, but it will still be checked
+again later on the CI when you submit your changes through GitLab for merging.
 
 We are working on making this less hasslesome.
 
-[gst-indent]: https://gitlab.freedesktop.org/gstreamer/gstreamer/-/blob/main/scripts/gst-indent-all
-
 Compiler requirements:
  - we are targetting the C99 compiler and preprocesser feature subset
    supported by gcc 5.4, clang and vs2017. Newer features can be
@@ -461,7 +457,7 @@ Other style guidelines:
    - declare variables inline (as opposed to only at the beginning of a block)
    - use advanced/nicer struct initialisers
 
-[gst-indent]: https://gitlab.freedesktop.org/gstreamer/gstreamer/tree/master/tools/gst-indent
+[gst-indent]: https://gitlab.freedesktop.org/gstreamer/gst-indent/
 [bitreader]: https://gstreamer.freedesktop.org/documentation/base/gstbitreader.html?gi-language=c#GstBitReader
 [bytereader]: https://gstreamer.freedesktop.org/documentation/base/gstbytereader.html?gi-language=c#GstByteReader
 

subprojects/gst-docs/markdown/frequently-asked-questions/developing.md

@@ -106,46 +106,31 @@ want it to do.
 
 ## What is the coding style for GStreamer code?
 
-Basically, the core and almost all plugin modules use K\&R with 2-space
+The indentation style for GStreamer C code is similar to K\&R with 2-space
-indenting. Just follow what's already there and you'll be fine. We only require
+indenting.
-code files to be indented, header may be indented manually for better
-readability. Please use spaces for indenting, not tabs, even in header files.
 
-Individual plugins in gst-plugins-\* or plugins that you want considered
+Consistent indentaiton is enforced only for C source files, we generally do
-for addition to these modules should use the same style. It's easier if
+not indent header files.
-everything is consistent. Consistency is, of course, the goal.
+
+In header files indentation is free-form, but please always use spaces and
+not tabs since editor settings with regard to tabs will vary. Please do not
+run the indenter on existing header files when making changes.
+
+Rust source files (.rs files) are indented with the standard `rustfmt`.
 
 One way to make sure you are following our coding style is to run your code
-(remember, only the `*.c` files, not the headers) through GNU Indent using the
+(remember, only the `*.c` files, not the headers) through the `gst-indent-1.0`
-following options:
+tool, which should be available in the uninstalled GStreamer development
-
+environment from version 1.23.1 onwards. Alternatively you can also get the
-```
+tool from the [gst-indent repository](https://gitlab.freedesktop.org/gstreamer/gst-indent/)
-indent \
+and build it yourself.
-  --braces-on-if-line \
-  --case-brace-indentation0 \
-  --case-indentation2 \
-  --braces-after-struct-decl-line \
-  --line-length80 \
-  --no-tabs \
-  --cuddle-else \
-  --dont-line-up-parentheses \
-  --continuation-indentation4 \
-  --honour-newlines \
-  --tab-size8 \
-  --indent-level2
-```
-
-There is also a `gst-indent` script in the GStreamer core source tree in the
-tools directory which wraps GNU Indent and uses the right options.
 
 The easiest way to get the indenting right is probably to develop against a git
 checkout. The local git commit hook will ensure correct indentation.
 
-Comments should be in `/* ANSI C comment style */` and code should generally
+Merge requests should always be made against git `main` branch and filed
-be compatible with ANSI C89, so please declare all variables at the beginning
+in GitLab.
-of the block, etc.
 
-Merge requests should ideally be made against git master or a recent release.
 Please don't send patches to the mailing list. They will likely get lost there.
 
 See [How to submit patches][submit-patches] for more details.