vala, valac: add pages (#4276)

Co-authored-by: dual <dual@dr.h>
Co-authored-by: Starbeamrainbowlabs <sbrl@starbeamrainbowlabs.com>

pages/common/vala.md

@@ -0,0 +1,17 @@
+# vala
+
+> Vala code runner.
+> Tutorial: <https://wiki.gnome.org/Projects/Vala/Tutorial>.
+> Doc homepage: <https://valadoc.org/>.
+
+- Run a vala file, with gtk+:
+
+`vala {{path/to/file.vala}} --pkg {{gtk+-3.0}}`
+
+- Display version info:
+
+`vala --version`
+
+- Display helper message:
+
+`vala --help`

pages/common/valac.md

@@ -0,0 +1,17 @@
+# valac
+
+> Vala code compiler.
+> Tutorial: <https://wiki.gnome.org/Projects/Vala/Tutorial>.
+> Doc homepage: <https://valadoc.org/>.
+
+- Compile a vala file, with gtk+:
+
+`valac {{path/to/file.vala}} --pkg {{gtk+-3.0}}`
+
+- Display version info:
+
+`valac --version`
+
+- Display helper message:
+
+`valac --help`