This applies especially in lsp-mode. Yasnippet snippets now show as
completion candidates if the word at point exactly matches a snippet
keyword, otherwise it'll fallback to normal lsp backed completion.
And it also supports completing file/directory names now too while
lsp-mode is active.
All this is done by modifying completion-at-point-functions after
lsp-mode has done it's trickery with it. Along with a dirty hack to
company-yasnippet to make it only activate on exact matches. Without
this hack, lsp backed completion rarely activates as snippets would have
higher priority if there's any partial matches.