Refine the default instructions for "Edit context" mode to improve clarity and formatting by using markdown headings for file paths

Author: robertpiosik

packages/vscode/package.json

@@ -2,7 +2,7 @@
   "name": "gemini-coder",
   "displayName": "Code Web Chat",
   "description": "Superfast AI coding (CWC)",
-  "version": "1.619.0",
+  "version": "1.620.0",
   "scripts": {
     "build": "npx vsce package --no-dependencies",
     "vscode:prepublish": "rimraf out && npm run compile",
@@ -582,9 +582,9 @@
           "scope": "resource",
           "description": "Style of generated code blocks in \"Edit context\" mode.",
           "default": {
-            "whole": "Whenever showing a new or updated file, print its path and a Markdown Code Block with file's full contents—as I have a disability which means I can't type and need to be able to just copy and paste. Provide brief explanations to the proposed changes.",
-            "truncated": "Whenever showing a new or updated file, print its path and a Markdown Code Block with truncated file's contents. To save space, unchanged parts should be hidden behind ellipsis comments, e.g. \"// ...\". Provide brief explanations to the proposed changes.",
-            "diff": "Whenever showing a new or updated file, use the the unified diff within a Markdown Code Block. Provide brief explanations to the proposed changes."
+            "whole": "Whenever showing a new or updated file: provide a brief explanation, use markdown heading for its path, and markdown code block for its full contents—as I have a disability which means I can't type and need to be able to just copy and paste.",
+            "truncated": "Whenever showing a new or updated file: provide a brief explanation, use markdown heading for its path, and markdown code block for its truncated contents—as a space saving measure (unchanged parts should be hidden behind ellipsis comments, e.g. \"// ...\").",
+            "diff": "Whenever showing a new or updated file: provide a brief explanation, and use unified diff within markdown code block."
           },
           "properties": {
             "whole": {