doc: install: Add shell completion set-up (#166)

docs/install.md

@@ -143,6 +143,27 @@ pip uninstall silkaj --user
 silkaj
 ```
 
+## Shell completion
+
+Set up the shell completion by adding following line in your shell configuration depending on your shell:
+
+=== "Bash"
+    ```title="$HOME/.bashrc"
+    eval "$(_SILKAJ_COMPLETE=bash_source silkaj)"
+    ```
+
+=== "Zsh"
+    ```title="$HOME/.zshrc"
+    eval "$(_SILKAJ_COMPLETE=zsh_source silkaj)"
+    ```
+
+=== "Fish"
+    ```title="$HOME/.config/fish/completions/silkaj.fish"
+    _SILKAJ_COMPLETE=fish_source silkaj | source
+    ```
+
+For further details checkout [Click documentation](https://click.palletsprojects.com/en/8.1.x/shell-completion/).
+
 ## Install to contribute
 
 Check out the [installation guide with Poetry](/contributing/install_poetry/).