️ REFACTOR: Adds .[all] for pip install (#898)

docs/contribute/intro.md

@@ -20,7 +20,7 @@ cd jupyter-book
 Next, install:
 
 ```bash
-pip install -e .[testing,code_style,sphinx]
+pip install -e .[all]
 ```
 
 This will install Jupyter Book locally, along with the packages needed to test it

setup.py

@@ -14,6 +14,7 @@ doc_reqs = [
     for ii in path_doc_reqs.read_text(encoding="utf8").split("\n")
     if not ii.startswith("#")
 ]
+# Test requirements
 test_reqs = [
     "coverage",
     "pytest>=3.6,<4",
@@ -31,6 +32,17 @@ test_reqs = [
     "beautifulsoup4",
     "cookiecutter",
 ]
+# Define all extras
+extras = {
+    "code_style": ["flake8<3.8.0,>=3.7.0", "black", "pre-commit==1.17.0"],
+    "sphinx": doc_reqs,
+    "testing": test_reqs,
+    "pdfhtml": ["pyppeteer"],
+}
+# Set alias for all extras with "all"
+extras["all"] = set(ii for jj in extras.values() for ii in jj)
+
+
 setup(
     name="jupyter-book",
     version=version,
@@ -69,12 +81,7 @@ setup(
         "sphinx-thebe>=0.0.6",
         "sphinx-panels~=0.5.2",
     ],
-    extras_require={
-        "code_style": ["flake8<3.8.0,>=3.7.0", "black", "pre-commit==1.17.0"],
-        "sphinx": doc_reqs,
-        "testing": test_reqs,
-        "pdfhtml": "pyppeteer",
-    },
+    extras_require=extras,
     entry_points={
         "console_scripts": [
             "jb = jupyter_book.commands:main",