[shell-scripts] add note about shellcheck

layers/+lang/shell-scripts/README.org

@@ -6,6 +6,7 @@
  - [[#description][Description]]
    - [[#features][Features]]
  - [[#install][Install]]
+   - [[#linting][Linting]]
  - [[#key-bindings][Key Bindings]]
 
 * Description
@@ -20,12 +21,16 @@ Supported scripting files:
 
 ** Features
 - Auto-completion using [[https://github.com/Alexander-Miller/company-shell][company-shell]]
+- =Sh= scripts linting using  [[https://www.shellcheck.net/][shellcheck]]
 
 * Install
 To use this configuration layer, add it to your =~/.spacemacs=. You will need to
 add =shell-scripts= to the existing =dotspacemacs-configuration-layers= list in this
 file.
 
+** Linting
+In order to enable =sh= scripts linting, install [[https://www.shellcheck.net/][shellcheck]].
+
 * Key Bindings
 
 | Key Binding | Description                                               |