chore: generated vimdoc (#182)

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

doc/feline.txt

@@ -901,9 +901,12 @@ configured and at least one LSP client to be attached to the current buffer,
 else they’ll have no output.
 
 The diagnostics provider also provides a utility function
-`require('feline.providers.lsp').diagnostics_exist(type)` for checking if any
-diagnostics of the provided type exists. The values of `type` must be one of
-`'Error'`, `'Warning'`, `'Hint'` or `'Information'`.
+`require('feline.providers.lsp').diagnostics_exist` for checking if any
+diagnostics exists. You can also optionally provide a `severity` function
+argument to only check for diagnostics of that severity. The value of
+`severity` must be one of the Neovim diagnostic API severities (eg:
+`vim.diagnostic.severity.WARN`). For more info on diagnostic severities, do
+`:help vim.diagnostic.severity` in Neovim.
 
 THEMES                                                         *feline-themes*