add zip/unzip

cheat/cheatsheets/unzip

@@ -0,0 +1,8 @@
+# Extract archive
+unzip archive.zip
+
+# Test integrity of archive
+unzip -tq archive.zip
+
+# List files and directories in a file
+unzip -l archive.zip

cheat/cheatsheets/zip

@@ -0,0 +1,5 @@
+# Create zip file
+zip archive.zip file1 directory/
+
+# To list, test and extract zip archives, see unzip
+cheat unzip