[Docs / Basic Usage] Use PowerShell on Windows

Further to #3372 and #3373, on Windows, you'd typically use PowerShell rather than CMD. PowerShell scripts end in `.ps1` while CMD "batch scripts" end in `.bat`.

docs/basic-usage.md

@@ -131,15 +131,15 @@ in order for the subsequent commands to run from within the virtual environment.
 
 
 Alternatively, to avoid creating a new shell, you can manually activate the
-virtual environment by running `source {path_to_venv}/bin/activate` (`{path_to_venv}\Scripts\activate.bat` on Windows).
+virtual environment by running `source {path_to_venv}/bin/activate` (`{path_to_venv}\Scripts\activate.ps1` on Windows PowerShell).
 To get the path to your virtual environment run `poetry env info --path`.
 You can also combine these into a nice one-liner, `source $(poetry env info --path)/bin/activate`
 To deactivate this virtual environment simply use `deactivate`.
 
-|                   | POSIX Shell                                     | Windows                               | Exit/Deactivate |
+|                   | POSIX Shell                                     | Windows (PowerShell)                  | Exit/Deactivate |
 | ----------------- | ----------------------------------------------- | ------------------------------------- | --------------- |
 | New Shell         | `poetry shell`                                  | `poetry shell`                        | `exit`          |
-| Manual Activation | `source {path_to_venv}/bin/activate`            | `{path_to_venv}\Scripts\activate.bat` | `deactivate`    |
+| Manual Activation | `source {path_to_venv}/bin/activate`            | `{path_to_venv}\Scripts\activate.ps1` | `deactivate`    |
 | One-liner         | `source $(poetry env info --path)/bin/activate` |                                       | `deactivate`    |