add vim cheatsheet

cheat/vim.md

@@ -19,3 +19,11 @@ Finally type `:wq` to save and close the file.
 ### Indent the whole file in VIM ([src](https://stackoverflow.com/questions/506075/how-do-i-fix-the-indentation-of-an-entire-file-in-vi))
 
 `gg=G`
+
+### Text selection ([Source](https://www.cs.swarthmore.edu/oldhelp/vim/selection.html))
+```
+V       - selects entire lines
+v       - selects range of text
+ctrl-v  - selects columns
+gv      - reselect block
+```