just: add page (#8119)

pages/common/just.md

@@ -0,0 +1,24 @@
+# just
+
+> Save and run project-specific commands.
+> More information: <https://github.com/casey/just>.
+
+- Run a recipe specified in the justfile:
+
+`just {{recipe}}`
+
+- Initialize new justfile in project root:
+
+`just --init`
+
+- Edit justfile in the default editor:
+
+`just -e`
+
+- List available recipes in the justfile:
+
+`just -l`
+
+- Print justfile:
+
+`just --dump`