Add support for tfsec Terraform linter (#4323)

doc/ale-supported-languages-and-tools.txt

@@ -597,6 +597,7 @@ Notes:
   * `terraform-ls`
   * `terraform-lsp`
   * `tflint`
+  * `tfsec`
 * Texinfo
   * `alex`
   * `cspell`

doc/ale-terraform.txt

@@ -114,6 +114,25 @@ g:ale_terraform_tflint_options                 *g:ale_terraform_tflint_options*
   to include '-f json' in your new value.
 
 
+===============================================================================
+tfsec                                                     *ale-terraform-tfsec*
+
+g:ale_terraform_tfsec_executable             *g:ale_terraform_tfsec_executable*
+                                             *b:ale_terraform_tfsec_executable*
+
+  Type: |String|
+  Default: `'tfsec'`
+
+  This variable can be changed to use a different executable for tfsec.
+
+g:ale_terraform_tfsec_options                *g:ale_terraform_tfsec_executable*
+                                             *b:ale_terraform_tfsec_executable*
+
+  Type: |String|
+  Default: `''`
+
+  This variable can be changed to pass custom CLI flags to tfsec.
+
 ===============================================================================
   vim:tw=78:ts=2:sts=2:sw=2:ft=help:norl:
 

doc/ale.txt

@@ -3261,6 +3261,7 @@ documented in additional help files.
     terraform-ls..........................|ale-terraform-terraform-ls|
     terraform-lsp.........................|ale-terraform-terraform-lsp|
     tflint................................|ale-terraform-tflint|
+    tfsec.................................|ale-terraform-tfsec|
   tex.....................................|ale-tex-options|
     chktex................................|ale-tex-chktex|
     cspell................................|ale-tex-cspell|