Re #1495 Clarify online documentation for skip-msys

Author: mpilgrem

doc/global_flags.md

@@ -210,8 +210,10 @@ Restrictions: Windows systems only
 
 Default: Disabled
 
-Enables/disables the skipping of installing MSYS2. For further information, see
-the documentation for the corresponding non-project specific configuration
+Enables/disables the skipping of checking for the Stack-supplied MSYS2 (and
+installing that MSYS2, if it is not installed) when Stack is setting up the
+environment. For further information, see the documentation for the
+corresponding non-project specific configuration
 [option](yaml_configuration.md#skip-msys).
 
 ## `--snapshot` option

doc/yaml_configuration.md

@@ -1678,16 +1678,21 @@ Restrictions: Windows systems only
 
 Default: `false`
 
-Command line equivalent (takes precedence): `--[no-]skip-msys` flag
+Command line equivalent (takes precedence):
+[`--[no-]skip-msys`](global_flags.md#-no-skip-msys-option) flag
 
-Skips checking for and installing MSYS2 when stack is Setting up the
-environment. This usually doesn't make sense in project-level configurations,
-just in `config.yaml`.
+Skips checking for the Stack-supplied MSYS2 (and installing that MSYS2, if it is
+not installed) when Stack is setting up the environment.
 
 ~~~yaml
 skip-msys: true
 ~~~
 
+!!! note
+
+    Usually, the use of this option does not make sense in project-level
+    configuration and it is used only in global configuration.
+
 ### snapshot-location-base
 
 [:octicons-tag-24: 2.5.1](https://github.com/commercialhaskell/stack/releases/tag/v2.5.1)