docs: add path docs

docs/src/SUMMARY.md

@@ -14,4 +14,5 @@
   - [API.Command](./plugin/interface/command.md)
   - [API.OS](./plugin/interface/os.md)
   - [API.Directories](./plugin/interface/dirs.md)
-  - [API.Network](./plugin/interface/network.md)
+  - [API.Network](./plugin/interface/network.md)
+  - [API.Path](./plugin/interface/path.md)

docs/src/plugin/interface/path.md

@@ -0,0 +1,35 @@
+# Path Functions
+
+> you can use path functions to operate valid path string
+
+### join(path: string, extra: string) -> string
+
+This function can help you extend a path, you can extend any path, dirname or filename.
+
+```lua
+local current_path = "~/hello/dioxus"
+local new_path = plugin.path.join(current_path, "world")
+-- new_path = "~/hello/dioxus/world"
+```
+
+### parent(path: string) -> string
+
+This function will return `path` parent-path string, back to the parent.
+
+```lua
+local current_path = "~/hello/dioxus"
+local new_path = plugin.path.parent(current_path)
+-- new_path = "~/hello/"
+```
+
+### exists(path: string) -> boolean
+
+This function can check some path (dir & file) is exists.
+
+### is_file(path: string) -> boolean
+
+This function can check some path is a exist file.
+
+### is_dir(path: string) -> boolean
+
+This function can check some path is a exist dir.