* pass --stdio flag to expert lsp server
expert requires --stdio to use stdio transport but the linter
definition launched it without the flag, so the server never
entered lsp mode
* handle client/registerCapability requests from lsp servers
some lsp servers like expert send a client/registerCapability
request after initialization to dynamically register capabilities,
if ale does not respond the server blocks and never processes
further messages like textDocument/didOpen
* add support for expert
* Refactor elixir expert linter from feedback
- Simplify configuration by removing executable lookup logic
- Update documentation to reflect current configuration options
- Rename test file and update assertions for the new configuration
* default to expert for the lsp
The install instructions included something I missed. It includes a
global install, where the default executable is just `expert`. I'll
default to that and review if I should should add a configuration for a
global config.
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Co-authored-by: Your Name <pmonson711@nfiindustries.com>