vim:keys: Use word boundaries with <leader>*

Ripgrep supports word boundaries, may as well use them to act closer to
`*` (:h star).

.config/vim/vimrc.d/40-keys.vim

@@ -91,7 +91,8 @@ endif
 vnoremap * y/\V<C-R>=escape(@",'/\')<CR><CR>
 vnoremap # y?\V<C-R>=escape(@",'?\')<CR><CR>
 
-nmap <leader>* :Rg <C-R><C-W><CR>
+" Use ripgrep as search-engine for `*`
+nmap <leader>* :Rg \b<C-R><C-W>\b<CR>
 
 " Select last pasted text in same visual mode as it was selected (v, V, or ^V)
 " Taken from: https://vim.fandom.com/wiki/Selecting_your_pasted_text