help: fix recipe-help msg for source libs

Author: bvdberg

compiler/main.c2

@@ -120,7 +120,7 @@ const char[] Recipe_help =
     "config <options>\n"
     "\n"
     "set <name>\n"
-    "   <files>\n"
+    "   <.c2 files>\n"
     "end\n"
     "\n"
     "executable <name>\n"
@@ -143,7 +143,7 @@ const char[] Recipe_help =
     "   $disable-asserts\n"
     "   $config <options>\n"
     "   $plugin <name> [<plugin-options>]\n"
-    "   $use <library-name> dynamic/static\n"
+    "   $use <library-name> dynamic/static/source\n"
     "   (set-name)\n"
     "   <file1.c2>\n"
     "   <file2.c2>\n"