fix: add readme

Author: HerringtonDarkholme

README.md

@@ -1 +1,71 @@
 # Monorepo for `@ast-grep/lang-*` packages
+
+This monorepo contains two folders: `packages` and `scripts`.
+
+## Packages
+
+Packages contain a list of prebuild tree-sitter grammars to use with the `@ast-grep/napi` package.
+
+Typical usage:
+
+1. Install the language package in your project
+
+```bash
+pnpm install @ast-grep/lang-{name}
+pnpm install @ast-grep/napi
+# install the tree-sitter-cli if no prebuild is available
+pnpm install @tree-sitter/cli --save-dev
+```
+
+2. Use the language package in your project
+
+```javascript
+import lang from '@ast-grep/lang-{name}'
+import { registerDynamicLanguage, parse } from '@ast-grep/napi'
+
+registerDynamicLanguage({ [langName]: lang })
+
+const sg = parse(langName, `your code`)
+sg.root().kind()
+```
+
+## Scripts
+
+Scripts contain a list of scripts to help with the development of the packages.
+
+### `scripts/create-lang`
+
+You can use `pnpm create @ast-grep/lang` to create a new language package.
+
+```bash
+# create a new language package in current directory
+pnpm create @ast-grep/lang
+# create package in a specific directory
+pnpm create @ast-grep/lang some-dir
+```
+
+You will be prompted to enter the language name, the language file extension, package name and tree-sitter grammar package.
+
+Note the tree-sitter grammar package is different from the package name. package name is the repo you create, tree-sitter package should be a package already published on npm.
+
+After the package is created, you can use these commands:
+
+```bash
+pnpm source # copy tree-sitter grammar files to the src folder
+pnpm build # build the tree-sitter grammar files to dynamic lib
+pnpm test # test the tree-sitter grammar files
+```
+
+You can edit `nursery.js` to add test case for your language.
+
+
+### `scripts/nursery`
+
+A build-time dependency for the `@ast-grep/lang-*` packages.
+It is used to copy and test the tree-sitter grammars.
+
+### `scripts/setup`
+
+A postinstall script to setup parser dynamic library for the `@ast-grep/lang-*` packages.
+If there is prebuild available, it will copy the dynamic library according to the platform and architecture.
+If there is no prebuild available, it will build the dynamic library from the tree-sitter grammar files.

scripts/create-lang/README.md

@@ -8,3 +8,21 @@ pnpm create @ast-grep/lang
 # create package in a specific directory
 pnpm create @ast-grep/lang some-dir
 ```
+
+You will be prompted to enter the language name, the language file extension, package name and tree-sitter grammar package.
+
+Note the tree-sitter grammar package is different from the package name. package name is the repo you create, tree-sitter package should be a package already published on npm.
+
+
+## Commands
+After the package is created, you can use these commands:
+
+```bash
+pnpm source # copy tree-sitter grammar files to the src folder
+pnpm build # build the tree-sitter grammar files to dynamic lib
+pnpm test # test the tree-sitter grammar files
+```
+
+### Test file
+
+You can edit `nursery.js` to add test case for your language.