fix: default path for --doc_out_path is the current directory

Back then the default path of doc.json was LOGPATH.
However the default path got lost after a refactoring in LuaLS#2821.
This commit reimplements the default path, but changes
the default to the current directory.

Author: AndreasMatthias

script/cli/doc/init.lua

@@ -242,6 +242,10 @@ function doc.runCLI()
         end)
         io.write('\x0D')
 
+        if not DOC_OUT_PATH then
+            DOC_OUT_PATH = fs.current_path():string()
+        end
+
         local ok, outPaths, err = dirty_export.serializeAndExport(docs, DOC_OUT_PATH)
         print(lang.script('CLI_DOC_DONE'))
         for i, path in ipairs(outPaths) do