Perfect the codebase for wamr-ide (#1817)

Fix errors and warnings reported by eslint
Add CONTRIBUTING document for vscode-extension

test-tools/wamr-ide/VSCode-Extension/.eslintrc.json

@@ -1,13 +1,12 @@
 {
     "root": true,
     "parser": "@typescript-eslint/parser",
+    "extends": ["plugin:@typescript-eslint/recommended"],
     "parserOptions": {
-        "ecmaVersion": 6,
+        "ecmaVersion": "latest",
         "sourceType": "module"
     },
-    "plugins": [
-        "@typescript-eslint"
-    ],
+    "plugins": ["@typescript-eslint"],
     "rules": {
         "@typescript-eslint/naming-convention": "warn",
         "@typescript-eslint/semi": "warn",
@@ -16,9 +15,5 @@
         "no-throw-literal": "warn",
         "semi": "off"
     },
-    "ignorePatterns": [
-        "out",
-        "dist",
-        "**/*.d.ts"
-    ]
+    "ignorePatterns": ["out", "dist", "**/*.d.ts"]
 }