Add "windows-latest" to build matrix

Author: amotl

.github/workflows/docs.yml

@@ -5,20 +5,24 @@ on:
     branches:
       - master
 
+defaults:
+  run:
+    shell: sh
+
 jobs:
   documentation:
     name: Build docs on ${{ matrix.os }} using Python ${{ matrix.python-version }}
     runs-on: ${{ matrix.os }}
 
     strategy:
       matrix:
-        os: [ubuntu-latest, macos-latest]
+        os: [ubuntu-latest, macos-latest, windows-latest]
         python-version: ["3.7", "3.8", "3.9"]
 
     steps:
       - uses: actions/checkout@v2
       - name: Set up Python
-        uses: actions/setup-python@v1
+        uses: actions/setup-python@v2
         with:
           python-version: ${{ matrix.python-version }}
       - name: Build docs

src/rules.mk

@@ -24,7 +24,7 @@ LOCAL_DIR       := $(patsubst %/src/,%,$(dir $(lastword $(MAKEFILE_LIST))))
 SRC_DIR         := $(LOCAL_DIR)/src
 ENV_DIR         := $(LOCAL_DIR)/.venv
 ACTIVATE        := $(ENV_DIR)/bin/activate
-PYTHON          := python3
+PYTHON          := python
 PIP             := $(PYTHON) -m pip
 SPHINXBUILD     := $(ENV_DIR)/bin/sphinx-build
 SPHINXAUTOBUILD := $(ENV_DIR)/bin/sphinx-autobuild