linux: Add cut command explanation (#177)

README.md

@@ -641,6 +641,9 @@ They take in input (<) and output for a given file (>) using stdin and stdout.
   - grep: a search tool. Used to search, count or match a text in a file:
     - searching for any line that contains a word in a file: `grep 'word' file.md`
     - or displaying the total number of times a string appears in a file: `grep -c 'This is a string' file.md`
+  - cut: a tool for cutting out selected portions of each line of a file:
+    - syntax: `cut OPTION [FILE]`
+      - cutting first two bytes from a word in a file: `cut -b 1-2 file.md`, output: `wo`
 </b></details>
 
 <details>