Previously, `tree-sitter build-wasm` had the ability to build WASM
by using docker to pull in an image with a complete emscripten toolchain.
This commit adds the ability to use podman to do the same thing.
Using podman requires two notable changes:
1. Using the fully-qualified image name. Docker defaults to prepending
`docker.io` to the image name, but podman does not.
2. Podman will mount the `/src/` volume as belonging to root unless
`--userns=keep-id` is passed. I think podman's different
volume-ownership is related to podman's daemonless execution and
`--uidmap` functionality, but I'm not 100% sure.
To test, I ran
```sh
script/fetch-fixtures
script/generate-fixtures
script/generate-fixtures-wasm # <- the important one!
```
which worked as well as the docker version.
This patch adds the `tree-sitter-config` crate, which manages
tree-sitter's configuration file. This new setup allows different
components to define their own serializable configuration types, instead
of having to create a single monolithic configuration type. But the
configuration itself is still stored in a single JSON file.
Before, the default location for the configuration file was
`~/.tree-sitter/config.json`. This patch updates the default location
to follow the XDG Base Directory spec (or other relevant platform-
specific spec). So on Linux, for instance, the new default location is
`~/.config/tree-sitter/config.json`. We will look in the new location
_first_, and fall back on reading from the legacy location if we can't
find anything.
This patch adds a new `tree-sitter-loader` crate, which holds the CLI's
logic for finding and building local grammar definitions at runtime.
This allows other command-line tools to use this logic too!
