Bug 1748845 - Update source-relative links in rust docs, r=firefox-source-docs-reviewers,sylvestre

Differential Revision: https://phabricator.services.mozilla.com/D135384

docs/testing-rust-code/index.md

@@ -2,8 +2,8 @@
 
 This page explains how to test and debug Rust code in Firefox.
 
-The [build documentation](../build/buildsystem/rust.html) explains how to add
-new Rust code to Firefox. The [code documentation](../writing-rust-code)
+The [build documentation](/build/buildsystem/rust.rst) explains how to add
+new Rust code to Firefox. The [code documentation](/writing-rust-code/index.md)
 explains how to write and work with Rust code in Firefox.
 
 ## Testing Mozilla crates
@@ -31,7 +31,7 @@ It's also possible to use `RUST_TESTS` in a different `moz.build` file. See
 `testing/geckodriver/moz.build` and the [geckodriver testing docs] for an
 example.
 
-[geckodriver testing docs]: ../testing/geckodriver/Testing.html
+[geckodriver testing docs]: /testing/geckodriver/Testing.md
 
 ### GTests
 
@@ -102,7 +102,7 @@ To restrict logging to child processes, use `RUST_LOG_CHILD` instead of
 Rust logging can also be forwarded to the [Gecko logger] for capture via
 `MOZ_LOG` and `MOZ_LOG_FILE`.
 
-[Gecko logger]: /xpcom/logging.html
+[Gecko logger]: /xpcom/logging.rst
 
 - When parsing modules from `MOZ_LOG`, modules containing `::` are considered
   to be Rust modules. To log everything in a top-level module like

docs/writing-rust-code/index.md

@@ -3,8 +3,8 @@
 This page explains how to write and work with Rust code in Firefox, with an
 emphasis on interoperation with C++ code.
 
-The [build documentation](../build/buildsystem/rust.html) explains how to add
-new Rust code to Firefox. The [test documentation](../testing-rust-code)
+The [build documentation](/build/buildsystem/rust.rst) explains how to add
+new Rust code to Firefox. The [test documentation](/testing-rust-code/index.md)
 explains how to test and debug Rust code in Firefox.
 
 ```{toctree}

docs/writing-rust-code/xpcom.md

@@ -21,7 +21,7 @@ xpcom = { path = "../../../xpcom/rust/xpcom" }
 file hierarchy.)
 
 Next hook it into the build system according to the [build
-documentation](../build/buildsystem/rust.html).
+documentation](/build/buildsystem/rust.rst).
 
 The Rust code will need to import some basic types. `xpcom::interfaces`
 contains all the usual `nsI` interfaces.
@@ -33,7 +33,7 @@ use std::sync::atomic::{AtomicBool, Ordering};
 use xpcom::{interfaces::nsISupports, RefPtr};
 ```
 
-The next part declares the implementation. 
+The next part declares the implementation.
 
 ```rust
 #[derive(xpcom)]
@@ -110,11 +110,11 @@ The following XPCOM components are written in Rust.
 - [bookmark_sync](https://searchfox.org/mozilla-central/source/toolkit/components/places/bookmark_sync),
   which [merges](https://mozilla.github.io/dogear) bookmarks from Firefox Sync
   with bookmarks in the Places database.
-  [There's also some docs on how Rust interacts with Sync](../services/sync/rust-engines.html)
+  [There's also some docs on how Rust interacts with Sync](/services/sync/rust-engines.rst)
 - [webext_storage_bridge](https://searchfox.org/mozilla-central/source/toolkit/components/extensions/storage/webext_storage_bridge),
   which powers the WebExtension storage.sync API. It's a self-contained example
   that pulls in a crate from application-services for the heavy lifting, wraps
   that up in a Rust XPCOM component, and then wraps the component in a JS
   interface. There's also some boilerplate there around adding a
   `components.conf` file, and a dummy C++ header that declares the component
-  constructor. [It has some in-depth documentation on how it hangs together](../toolkit/components/extensions/webextensions/webext-storage.html).
+  constructor. [It has some in-depth documentation on how it hangs together](../toolkit/components/extensions/webextensions/webext-storage.rst).