Merge #5885

5885: Make inlay hints colors more configurable r=matklad a=Veetaha

**[BREAKING CHANGE]**

Tackles https://github.com/rust-analyzer/rust-analyzer/issues/5337#issuecomment-680018601 and generally related to #5337.

Added `foreground/background` color configurations with optional more specific overrides `foreground.(type|parameter|chaining)Hints`.

One problem I see is that the config keys are long and don't fit into the on-hover hints in the `settings.json` file entirely...

<details>
<summary>Demo</summary>

![demo](https://user-images.githubusercontent.com/36276403/91238334-77fc3b00-e745-11ea-836b-2822015ece98.gif)

</details>

Co-authored-by: Veetaha <[email protected]>

1 files changed, 24 insertions, 0 deletions

diff --git a/docs/user/manual.adoc b/docs/user/manual.adoc
index 8c966288b..b15c9ee7f 100644
--- a/docs/user/manual.adoc
+++ b/docs/user/manual.adoc
@@ -367,6 +367,30 @@ include::./generated_assists.adoc[]
 
 == Editor Features
 === VS Code
+
+==== Color configurations
+
+It is possible to change the foreground/background color of inlay hints. Just add this to your
+`settings.json`:
+
+[source,jsonc]
+----
+{
+  "workbench.colorCustomizations": {
+    // Name of the theme you are currently using
+    "[Default Dark+]": {
+      "rust_analyzer.inlayHints.foreground": "#868686f0",
+      "rust_analyzer.inlayHints.background": "#3d3d3d48",
+
+      // Overrides for specific kinds of inlay hints
+      "rust_analyzer.inlayHints.foreground.typeHints": "#fdb6fdf0",
+      "rust_analyzer.inlayHints.foreground.paramHints": "#fdb6fdf0",
+      "rust_analyzer.inlayHints.background.chainingHints": "#6b0c0c81"
+    }
+  }
+}
+----
+
 ==== Special `when` clause context for keybindings.
 You may use `inRustProject` context to configure keybindings for rust projects only. For example:
 [source,json]