prepare release

Author: ota-meshi

Diff for: docs/implementing-custom-template-tokenizers.md

@@ -1,5 +1,7 @@
 # Implementing custom template tokenizers
 
+**This is an experimental feature. It may be changed or deleted without notice in the minor version.**
+
 A custom template tokenizer needs to create two types of tokens from the text it is given:
 
 - Low level [tokens](https://github.com/vuejs/vue-eslint-parser/blob/master/src/ast/tokens.ts), which can be of an [existing HTML type](https://github.com/vuejs/vue-eslint-parser/blob/master/src/html/tokenizer.ts#L59) or even new types.

Diff for: package.json

@@ -1,4 +1,7 @@
 {
+  "publishConfig": {
+    "tag": "next"
+  },
   "name": "vue-eslint-parser",
   "version": "8.3.0",
   "description": "The ESLint custom parser for `.vue` files.",