Use jsonc to parse babelrc comments in markdown files (#8643) [skip ci]

* [skip ci] use markdown jsonc to parse comments in README files

* [skip ci] change json to jsonc type in other markdown files

codemods/babel-plugin-codemod-object-assign-to-object-spread/README.md

@@ -36,7 +36,7 @@ npm install --save-dev @babel/plugin-codemod-object-assign-to-object-spread
 
 **.babelrc**
 
-```json
+```jsonc
 {
   "plugins": ["@babel/plugin-codemod-object-assign-to-object-spread"]
 }

codemods/babel-plugin-codemod-optional-catch-binding/README.md

@@ -34,7 +34,7 @@ npm install --save-dev @babel/plugin-codemod-optional-catch-binding
 
 **.babelrc**
 
-```json
+```jsonc
 {
   "plugins": ["@babel/plugin-codemod-optional-catch-binding"]
 }

packages/babel-preset-stage-0/README.md

@@ -8,7 +8,7 @@ For a more automatic migration, we have updated [babel-upgrade](https://github.c
 
 If you want the same configuration as before:
 
-```json
+```jsonc
 {
   "plugins": [
     // Stage 0

packages/babel-preset-stage-1/README.md

@@ -8,7 +8,7 @@ For a more automatic migration, we have updated [babel-upgrade](https://github.c
 
 If you want the same configuration as before:
 
-```json
+```jsonc
 {
   "plugins": [
     // Stage 1

packages/babel-preset-stage-2/README.md

@@ -8,7 +8,7 @@ For a more automatic migration, we have updated [babel-upgrade](https://github.c
 
 If you want the same configuration as before:
 
-```json
+```jsonc
 {
   "plugins": [
     // Stage 2