docs: add full docs for additionalTextEdits

Author: aminya

lib/adapters/autocomplete-adapter.ts

@@ -496,7 +496,15 @@ export default class AutocompleteAdapter {
     suggestion.text = textEdit.newText
   }
 
-  /** Handle additional text edits after a suggestion insert, e.g. `additionalTextEdits`. */
+  /**
+   * Handle additional text edits after a suggestion insert, e.g. `additionalTextEdits`.
+   *
+   * `additionalTextEdits` are An optional array of additional text edits that are applied when selecting this
+   * completion. Edits must not overlap (including the same insert position) with the main edit nor with themselves.
+   *
+   * Additional text edits should be used to change text unrelated to the current cursor position (for example adding an
+   * import statement at the top of the file if the completion item will insert an unqualified type).
+   */
   public static applyAdditionalTextEdits(event: ac.SuggestionInsertedEvent): void {
     const suggestion = event.suggestion as SuggestionBase
     const additionalEdits = suggestion.completionItem?.additionalTextEdits