docs: migrate to mdbook

docs/src/cli/version.md

@@ -0,0 +1,24 @@
+# `tree-sitter version`
+
+The `version` command upgrades the version of your grammar.
+
+```bash
+tree-sitter version <VERSION> # Aliases: publish
+```
+
+This will update the version in several files, if they exist:
+
+* tree-sitter.json
+* Cargo.toml
+* Cargo.lock
+* package.json
+* package-lock.json
+* Makefile
+* CMakeLists.txt
+* pyproject.toml
+
+As a grammar author, you should keep the version of your grammar in sync across
+different bindings. However, doing so manually is error-prone and tedious, so
+this command takes care of the burden. If you are using a version control system,
+it is recommended to commit the changes made by this command, and to tag the
+commit with the new version.