luajit: add page, lua: update page (#10206)

pages/common/lua.md

@@ -9,7 +9,7 @@
 
 - Execute a Lua script:
 
-`lua {{script_name.lua}} {{--optional-argument}}`
+`lua {{path/to/script.lua}} {{--optional-argument}}`
 
 - Execute a Lua expression:
 

pages/common/luajit.md

@@ -0,0 +1,17 @@
+# luajit
+
+> A just-in-time compiler (JIT) for the Lua programming language.
+> See also: `lua`.
+> More information: <https://luajit.org/luajit.html>.
+
+- Start an interactive Lua shell:
+
+`luajit`
+
+- Execute a Lua script:
+
+`luajit {{path/to/script.lua}} {{--optional-argument}}`
+
+- Execute a Lua expression:
+
+`luajit -e '{{print("Hello World")}}'`