docs: mention advanced semantic token options

They are:

"ui.noSemanticNumber": true,
"ui.noSemanticString": true

Updates #2682

Change-Id: I942b735af16ed7d070615baad231df4cdcba5d73
GitHub-Last-Rev: 9ac0a3e
GitHub-Pull-Request: #2684
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/471280
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
TryBot-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Peter Weinberger <pjw@google.com>
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
Auto-Submit: Hyang-Ah Hana Kim <hyangah@gmail.com>

Author: hyangah

docs/features.md

@@ -112,7 +112,18 @@ Quickly toggle between a file and its corresponding test file by using the [`Go:
 
 The default syntax highlighting for Go files is implemented in Visual Studio Code using TextMate grammar, not by this extension.
 
-If you are using `gopls`, you can enable [Semantic Highlighting](https://code.visualstudio.com/api/language-extensions/semantic-highlight-guide) for more accurate syntax highlighting based on semantic tokenization using `"gopls": { "ui.semanticTokens": true }`.
+If you are using `gopls`, you can enable [Semantic Highlighting](https://code.visualstudio.com/api/language-extensions/semantic-highlight-guide) for more accurate syntax highlighting based on semantic tokenization using this setting:
+
+```
+"gopls": {
+  "ui.semanticTokens": true,
+
+  // you can optionally turn on these features for more colors
+  // see https://go.dev/issue/45753 and https://go.dev/issue/45792 
+  "ui.noSemanticString": true,  // delegates string syntax highlighting to vscode
+  "ui.noSemanticNumber": true,  // delegates number syntax highlighting to vscode
+}
+```
 
 ### Go template syntax highlighting