update vim syntax

vim/vim-completion.md

@@ -1,16 +1,16 @@
 ---
 title: "vim completion"
-tags: [ "vim" ]
+tags: [ "vim", "completion" ]
 ---
 
 Complete the word by searching for the *n*ext similar word:
 
-> C-n
+`C-n`
 
 Complete the word by searching for a *p*revious similar word:
 
-> C-p
+`C-p`
 
 Complete the full line:
 
-> C-x C-l
+`C-x C-l`