Fix broken references in documentation

.github/workflows/ci.yml

@@ -12,6 +12,16 @@ on:
     - cron: 0 0 * * MON # Run every Monday at 00:00 UTC
 
 jobs:
+  docs:
+    name: docs
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-python@v2
+      - run: pip install nox
+      - run: nox -s docs
+
   determine-changes:
     runs-on: ubuntu-latest
     outputs:

docs/html/reference/requirements-file-format.md

@@ -1,3 +1,5 @@
+(requirements-file-format)=
+
 # Requirements File Format
 
 Requirements files serve as a list of items to be installed by pip, when

docs/html/user_guide.rst

@@ -113,7 +113,7 @@ installed using :ref:`pip install` like so:
 
       py -m pip install -r requirements.txt
 
-Details on the format of the files are here: :ref:`Requirements File Format`.
+Details on the format of the files are here: :ref:`requirements-file-format`.
 
 Logically, a Requirements file is just a list of :ref:`pip install` arguments
 placed in a file. Note that you should not rely on the items in the file being
@@ -185,7 +185,7 @@ not by discovering ``requirements.txt`` files embedded in projects.
 
 See also:
 
-* :ref:`Requirements File Format`
+* :ref:`requirements-file-format`
 * :ref:`pip freeze`
 * `"setup.py vs requirements.txt" (an article by Donald Stufft)
   <https://caremad.io/2013/07/setup-vs-requirement/>`_