Problem: Can't uninstall custom parsers without queries since
`installed_parsers` only iterates over installed queries (to include
query-only languages, and to avoid string manipulation).
Solution: Iterate over both queries and parsers to collect list of
installed languages (optionally only queries or only parsers).
Instead, call `require('nvim-treesitter').install( { ... } )` manually.
This gives users full control over how they want to install parsers
(sync, from grammar, limited concurrency) and obviates the need for
calling `setup` for most users.
Problem: Tracking parser revision in lockfile and allowing override
through the parsers module complicates the code. In addition, only
revision changes are handled robustly, not changes to other installation
info.
Solution: Track parser revision in the parsers module directly. Reload
parser table on every install or update call. Support modifying parser
table in a `User TSUpdate` autocommand.
Tier 1: Stable
Tier 2: Core (maintained by org members)
Tier 3: Community (maintained by external contributors, to varying
degree)
Tier 4: Unsupported (lacking active maintainer or declared
experimental); skipped in lockfile update and ignored for automatic
install by default
