Fix path of lua module

diff --git a/src/lua-apk.c b/lua/apk.c
similarity index 100%
rename from src/lua-apk.c
rename to lua/apk.c
diff --git a/lua/meson.build b/lua/meson.build
new file mode 100644
index 0000000..03b02e8
--- /dev/null
+++ b/lua/meson.build
@@ -0,0 +1,19 @@
+luaapk_src = [
+	'apk.c',
+]
+
+libluaapk = shared_module(
+	'apk',
+	luaapk_src,
+	dependencies: [
+		lua_dep,
+		libapk_dep,
+		apk_deps,
+		libportability_dep.partial_dependency(includes: true),
+	],
+	install: not subproject,
+	install_dir: get_option('libdir') / 'lua' / get_option('lua_version'),
+	include_directories: ['../src'],
+	name_prefix: '',
+	c_args: apk_cargs,
+)
--- a/meson.build
+++ b/meson.build
@@ -40,4 +40,7 @@ else
 	libfetch_dep = dependency('', required: false)
 endif
 subdir('src')
+if(lua_dep.found())
+	subdir('lua')
+endif
 subdir('tests')
--- a/src/meson.build
+++ b/src/meson.build
@@ -172,26 +172,6 @@ if not subproject
 	)
 endif
 
-if(lua_dep.found())
-	luaapk_src = [
-		'lua-apk.c',
-	]
-
-	libluaapk = library(
-		'luaapk',
-		luaapk_src,
-		dependencies: [
-			lua_dep,
-			libapk_dep,
-			apk_deps,
-			libportability_dep.partial_dependency(includes: true),
-		],
-		install: true,
-		install_dir: lua_dep.get_variable(pkgconfig: 'libdir'),
-		c_args: apk_cargs,
-	)
-endif
-
 apk_exe = executable(
 	'apk',
 	apk_src,