Problem:
Users using `vim.lsp.start` directly (instead of nvim-lspconfig) need
more visibility for troubleshooting. For example, troubleshooting
unnecesary servers or servers that aren't attaching to expected buffers.
Solution:
Mention attached buffers in the `:checkhealth lsp` report.
Example:
vim.lsp: Active Clients ~
- clangd (id=1, root_dir=~/dev/neovim, attached_to=[7])
- lua_ls (id=2, root_dir=~/dev/neovim, attached_to=[10])