Update DEVELOPERS-GUIDE.md
Correct  mistake for windows developer
@@ -23,7 +23,8 @@ $ virtualenv venv
**Step 2.1** For uvision progen compilation, update tools and generate project files. **This should be done every time you pull new changes**
```
-$ venv/Scripts/activate
+$ venv/Scripts/activate (For Linux)
+$ venv/Scripts/activate.bat (For Windows)
$ pip install -r requirements.txt
$ progen generate -t uvision
$ venv/Scripts/deactivate
@@ -31,7 +32,8 @@ $ venv/Scripts/deactivate
**Step 2.2** For mbed cli project compilation
```
-$ venv/Scripts/activate
+$ venv/Scripts/activate (For Linux)
+$ venv/Scripts/activate.bat (For Windows)
$ pip install -r requirements.txt
$ mbed deploy
$ mbed config root .
