Cheatsheets added

- apk: Alpine Linux package manager
 - gcc: GNU C Compiler
 - grep: Pattern matcher in files or pipes
 - vim: Vi IMproved

cheatsheets/vim

@@ -0,0 +1,8 @@
+# Appending
+a - drops vim into append mode
+i - enters append mode without character skip
+
+# File management
+:w - writes (saves) file
+:q - quits
+;q! - quits without saving changes