Add style guide documentation.

docs/markdown/Style-guide.md

@@ -0,0 +1,36 @@
+---
+short-description: Style recommendations for Meson files
+...
+
+# Style recommendations
+
+This page lists some recommendations on organizing and formatting your
+Meson build files.
+
+## Tabs or spaces?
+
+Always spaces.
+
+## Naming options
+
+There are two ways of naming project options. As an example for
+booleans the first one is `foo` and the second one is
+`enable-foo`. The former style is recommended, because in Meson
+options have strong type, rather than being just strings.
+
+You should try to name options the same as is common in other
+projects. This is especially important for yielding options, because
+they require that both the parent and subproject options have the same
+name.
+
+# Global arguments
+
+Prefer `add_project_arguments` to `add_global_arguments` because using
+the latter prevents using the project as a subproject.
+
+# Cross compilation arguments
+
+Try to keep cross compilation arguments away from your build files as
+much as possible. Keep them in the cross file instead. This adds
+portability, since all changes needed to compile to a different
+platform are isolated in one place.

docs/sitemap.txt

@@ -52,6 +52,7 @@ index.md
 		Project-templates.md
 	Reference-manual.md
 	Reference-tables.md
+	Style-Guide.md
 	FAQ.md
 	Reproducible-builds.md
 	howtox.md