consolidate git extensions

related to #43978

extensions/git/package.json

@@ -1,8 +1,8 @@
 {
   "name": "git",
+  "displayName": "%displayName%",
+  "description": "%description%",
   "publisher": "vscode",
-  "displayName": "git",
-  "description": "Git",
   "version": "0.0.1",
   "engines": {
     "vscode": "^1.5.0"
@@ -18,7 +18,8 @@
   "main": "./out/main",
   "scripts": {
     "compile": "gulp compile-extension:git",
-    "watch": "gulp watch-extension:git"
+    "watch": "gulp watch-extension:git",
+    "update-grammar": "node ./build/update-grammars.js"
   },
   "contributes": {
     "commands": [
@@ -1020,7 +1021,69 @@
           "highContrast": "#8db9e2"
         }
       }
-    ]
+    ],
+    "languages": [
+      {
+        "id": "git-commit",
+        "aliases": [
+          "Git Commit Message",
+          "git-commit"
+        ],
+        "filenames": [
+          "COMMIT_EDITMSG",
+          "MERGE_MSG"
+        ],
+        "configuration": "./languages/git-commit.language-configuration.json"
+      },
+      {
+        "id": "git-rebase",
+        "aliases": [
+          "Git Rebase Message",
+          "git-rebase"
+        ],
+        "filenames": [
+          "git-rebase-todo"
+        ],
+        "configuration": "./languages/git-rebase.language-configuration.json"
+      },
+      {
+        "id": "diff",
+        "aliases": [
+          "Diff",
+          "diff"
+        ],
+        "extensions": [
+          ".patch",
+          ".diff",
+          ".rej"
+        ],
+        "configuration": "./languages/diff.language-configuration.json"
+      }
+    ],
+    "grammars": [
+      {
+        "language": "git-commit",
+        "scopeName": "text.git-commit",
+        "path": "./syntaxes/git-commit.tmLanguage.json"
+      },
+      {
+        "language": "git-rebase",
+        "scopeName": "text.git-rebase",
+        "path": "./syntaxes/git-rebase.tmLanguage.json"
+      },
+      {
+        "language": "diff",
+        "scopeName": "source.diff",
+        "path": "./syntaxes/diff.tmLanguage.json"
+      }
+    ],
+    "configurationDefaults": {
+      "[git-commit]": {
+        "editor.rulers": [
+          72
+        ]
+      }
+    }
   },
   "dependencies": {
     "byline": "^5.0.0",