Add initial API doc configuration

Signed-off-by: David Horstmann <david.horstmann@arm.com>
diff --git a/docs/requirements.txt b/docs/requirements.txt
new file mode 100644
index 0000000..9d57fad
--- /dev/null
+++ b/docs/requirements.txt
@@ -0,0 +1,82 @@
+#
+# This file is autogenerated by pip-compile with Python 3.8
+# by the following command:
+#
+#    pip-compile requirements.in
+#
+alabaster==0.7.13
+    # via sphinx
+babel==2.12.1
+    # via sphinx
+beautifulsoup4==4.11.2
+    # via exhale
+breathe==4.35.0
+    # via
+    #   -r requirements.in
+    #   exhale
+certifi==2022.12.7
+    # via requests
+charset-normalizer==3.1.0
+    # via requests
+docutils==0.17.1
+    # via
+    #   breathe
+    #   exhale
+    #   sphinx
+    #   sphinx-rtd-theme
+exhale==0.3.6
+    # via -r requirements.in
+idna==3.4
+    # via requests
+imagesize==1.4.1
+    # via sphinx
+importlib-metadata==6.0.0
+    # via sphinx
+jinja2==3.1.2
+    # via sphinx
+lxml==4.9.2
+    # via exhale
+markupsafe==2.1.2
+    # via jinja2
+packaging==23.0
+    # via sphinx
+pygments==2.14.0
+    # via sphinx
+pytz==2022.7.1
+    # via babel
+requests==2.28.2
+    # via sphinx
+six==1.16.0
+    # via exhale
+snowballstemmer==2.2.0
+    # via sphinx
+soupsieve==2.4
+    # via beautifulsoup4
+sphinx==4.5.0
+    # via
+    #   breathe
+    #   exhale
+    #   sphinx-rtd-theme
+sphinx-rtd-theme==1.2.0
+    # via -r requirements.in
+sphinxcontrib-applehelp==1.0.4
+    # via sphinx
+sphinxcontrib-devhelp==1.0.2
+    # via sphinx
+sphinxcontrib-htmlhelp==2.0.1
+    # via sphinx
+sphinxcontrib-jquery==2.0.0
+    # via sphinx-rtd-theme
+sphinxcontrib-jsmath==1.0.1
+    # via sphinx
+sphinxcontrib-qthelp==1.0.3
+    # via sphinx
+sphinxcontrib-serializinghtml==1.1.5
+    # via sphinx
+urllib3==1.26.15
+    # via requests
+zipp==3.15.0
+    # via importlib-metadata
+
+# The following packages are considered to be unsafe in a requirements file:
+# setuptools