add notes for Windows (#10)

* add notes for Windows

* windows commands for downloading sources and skipping packages

* COLCON_IGORE -> COLCON_IGNORE

* Common download instructions

* avoid tmp in windows note

* remove tmp from venv

* wording skip vs. ignore

* use backslashes for Windows commands

* mention argcomplete

* add mention bat on windows

* remove usage of call when invoking script

developer/bootstrap.rst

@@ -19,9 +19,13 @@ While not strictly necessary it is recommended to use a virtual environment for
 
 .. code-block:: bash
 
-    $ mkdir /tmp/colcon-venv
-    $ python3 -m venv /tmp/colcon-venv
-    $ . /tmp/colcon-venv/bin/activate
+    $ mkdir colcon-venv
+    $ python3 -m venv colcon-venv
+    $ . colcon-venv/bin/activate
+
+.. note::
+
+    On Windows the Python 3 executable is likely named ``python`` and the activation script is invoked with ``colcon-venv\Scripts\activate``
 
 You might want to make sure that the venv is using up-to-date versions of the some foundational packages.
 
@@ -34,16 +38,25 @@ Fetch the sources
 
 .. code-block:: bash
 
-    $ mkdir /tmp/colcon-from-source && cd /tmp/colcon-from-source
-    $ wget https://raw.githubusercontent.com/colcon/colcon.readthedocs.org/master/colcon.repos
+    $ mkdir colcon-from-source && cd colcon-from-source
+    $ curl --output colcon.repos https://raw.githubusercontent.com/colcon/colcon.readthedocs.org/master/colcon.repos
     $ mkdir src
     $ vcs import src < colcon.repos
 
 .. note::
 
     Depending on your platform you might not want to use all cloned packages.
-    E.g. on Windows you might want to remove / skip the packages ``colcon-bash`` and ``colcon-argcomplete``.
-    If you don't use PowerShell you might want to remove / skip the package ``colcon-powershell``.
+    On Windows you must ignore or remove ``colcon-argcomplete``, and may want to do the same for ``colcon-bash``.
+    If you don't use PowerShell you might want to ignore / remove the package ``colcon-powershell``.
+    To ignore a package add an empty file named COLCON_IGNORE to the folder.
+
+Ignore ``colcon-argcomplete`` and ``colcon-bash`` on Windows.
+
+.. code-block:: dosbatch
+
+    > type nul > src\colcon-argcomplete\COLCON_IGNORE
+    > type nul > src\colcon-bash\COLCON_IGNORE
+
 
 Build the sources - first time
 ------------------------------
@@ -67,6 +80,12 @@ Build the sources - second time
     $ . install/local_setup.sh
     $ colcon build
 
+.. note::
+
+    On Windows the setup file ends with ``.bat`` and is just being called.
+    Also the ``colcon`` executable can't be invoked directly here since while it is being used it can't be overwritten by the build.
+    Instead invoke the following command: ``python install\colcon-core\Scripts\colcon-script.py build``.
+
 .. note::
 
     The second build will process packages in parallel as long as their dependencies are finished.
@@ -81,5 +100,5 @@ To use the full functionality you can source the generated script for your shell
 
 .. note::
 
-    With bash you should now also have completion for all arguments.
+    With bash you should now also have completion for all arguments if you have the Python package `argcomplete <https://pypi.org/project/argcomplete/>`_ installed.
     Try typing ``colcon <tab>`` to see the completion of global options and verbs.