Add wisdoms to Cheatsheet

doc/cheatsheet.md

@@ -1,18 +1,50 @@
-List of popular commands and shortcuts
+# List of popular commands and shortcuts
 
+## Bash
 
+### Previous command
 ```bash
-# from previous comand
 !0 - command itself
 !^ - first argument
 !$ - last argument
 !* - all arguments
+!! - full command
+```
 
-# Kubernetes
+### Useable commands
+```bash
+# step back
+cd -
+sudo su
+```
+
+### To explore
+```bash
+ag
+fzf
+fd
+```
+
+### Script errors
+```bash
+set -o errexit
+set -o nounset
+set -o pipefail
+```
+
+### A shell script static analysis tool
+[ShellCheck](https://github.com/koalaman/shellcheck)
+
+
+## Kubernetes
+```bash
 # ~/.kube/config
 kubectl config get-contexts
 kubectl config use-context <context>
+```
 
-# AWS
+## AWS
+```bash
 aws eks update-kubeconfig --name nas
 ```
+