docs: Validate JSON snippets (settings, keymap, tasks, etc) (#40043)

Closes #ISSUE

Release Notes:

- N/A *or* Added/Fixed/Improved ...

docs/src/languages/rust.md

@@ -16,7 +16,7 @@ TBD: Provide explicit examples not just `....`
 
 The following configuration can be used to change the inlay hint settings for `rust-analyzer` in Rust:
 
-```json
+```json [settings]
 {
   "lsp": {
     "rust-analyzer": {
@@ -43,7 +43,7 @@ See [Inlay Hints](https://rust-analyzer.github.io/book/features.html#inlay-hints
 
 The `rust-analyzer` target directory can be set in `initialization_options`:
 
-```json
+```json [settings]
 {
   "lsp": {
     "rust-analyzer": {
@@ -67,7 +67,7 @@ By default, Zed will try to find a `rust-analyzer` in your `$PATH` and try to us
 
 If you want to install pre-release `rust-analyzer` version instead you can instruct Zed to do so by setting `pre_release` to `true` in your `settings.json`:
 
-```json
+```json [settings]
 {
   "lsp": {
     "rust-analyzer": {
@@ -81,7 +81,7 @@ If you want to install pre-release `rust-analyzer` version instead you can instr
 
 If you want to disable Zed looking for a `rust-analyzer` binary, you can set `ignore_system_version` to `true` in your `settings.json`:
 
-```json
+```json [settings]
 {
   "lsp": {
     "rust-analyzer": {
@@ -95,7 +95,7 @@ If you want to disable Zed looking for a `rust-analyzer` binary, you can set `ig
 
 If you want to use a binary in a custom location, you can specify a `path` and optional `arguments`:
 
-```json
+```json [settings]
 {
   "lsp": {
     "rust-analyzer": {
@@ -114,7 +114,7 @@ This `"path"` has to be an absolute path.
 
 If you want rust-analyzer to provide diagnostics for a target other than your current platform (e.g. for windows when running on macOS) you can use the following Zed lsp settings:
 
-```json
+```json [settings]
 {
   "lsp": {
     "rust-analyzer": {
@@ -139,7 +139,7 @@ rustup target list --installed
 Zed provides tasks using tree-sitter, but rust-analyzer has an LSP extension method for querying file-related tasks via LSP.
 This is enabled by default and can be configured as
 
-```json
+```json [settings]
 "lsp": {
   "rust-analyzer": {
     "enable_lsp_tasks": true,
@@ -191,7 +191,7 @@ Check on save feature is responsible for returning part of the diagnostics based
 Consider more `rust-analyzer.cargo.` and `rust-analyzer.check.` and `rust-analyzer.diagnostics.` settings from the manual for more fine-grained configuration.
 Here's a snippet for Zed settings.json (the language server will restart automatically after the `lsp.rust-analyzer` section is edited and saved):
 
-```json
+```json [settings]
 {
   "lsp": {
     "rust-analyzer": {
@@ -225,7 +225,7 @@ Here's a snippet for Zed settings.json (the language server will restart automat
 If you want rust-analyzer to analyze multiple Rust projects in the same folder that are not listed in `[members]` in the Cargo workspace,
 you can list them in `linkedProjects` in the local project settings:
 
-```json
+```json [settings]
 {
   "lsp": {
     "rust-analyzer": {
@@ -241,7 +241,7 @@ you can list them in `linkedProjects` in the local project settings:
 
 There's a way to get custom completion items from rust-analyzer, that will transform the code according to the snippet body:
 
-```json
+```json [settings]
 {
   "lsp": {
     "rust-analyzer": {
@@ -300,7 +300,7 @@ For more control, you can add debug configurations to `.zed/debug.json`. See the
 
 ### Build binary then debug
 
-```json
+```json [debug]
 [
   {
     "label": "Build & Debug native binary",
@@ -321,7 +321,7 @@ For more control, you can add debug configurations to `.zed/debug.json`. See the
 
 When you use `cargo build` or `cargo test` as the build command, Zed can infer the path to the output binary.
 
-```json
+```json [debug]
 [
   {
     "label": "Build & Debug native binary",