add instructions to run wails v3 examples. (#2854)

* add instructions to run wails v3 examples.

* Update README.md

v3/README.md

@@ -1,3 +1,28 @@
 # v3
 
-This directory is experimental. It probably won't work for you. There's no support for this directory. Dragons be here. You have been warned!
+This directory is experimental. It probably won't work for you. There's no support for this directory. Dragons be here. You have been warned!
+
+## Run examples
+follow these steps to run the examples:
+-  clone the repo
+```cmd
+git clone https://github.com/wailsapp/wails.git
+```
+-  switch to v3-alpha branch
+```cmd
+git checkout v3-alpha
+```
+-  install dependencies 
+  ```cmd 
+go mod tidy
+```
+-  run the example you want
+```cmd
+cd v3/examples/(example you want)
+```
+```cmd
+go mod tidy
+```
+```cmd
+go run main.go
+```