Add a command to remove semester suffix

Like S7 or S79 in subjects.

Guides/ics-vim.md

@@ -48,3 +48,18 @@ SUMMARY:TP,CCUBE
 SUMMARY:CM,CCUBE
 ```
 
+## Remove semester from subjects
+
+Commant vim : `:%s/S[3579]\+//`
+
+Before :
+```
+SUMMARY:TD,EPSS79
+SUMMARY:TD,ALLS7
+```
+
+After :
+```
+SUMMARY:TD,EPS
+SUMMARY:TD,ALL
+```