Use furo docs theme

This MR migrates the online documentation to use the furo theme which provides numerous improvements over sphinx_rtd_theme, in particular automatic dark mode themeing.

docs/conf.py

@@ -21,21 +21,9 @@ version = re.split(r'[\w-]', gwdatafind.__version__)[0]
 source_suffix = '.rst'
 master_doc = 'index'
 
-<<<<<<< HEAD
-# General information about the project.
-project = "gwdatafind"
-copyright = "2018-2021, Cardiff University"
-author = "Duncan Macleod"
-
-# The short X.Y version.
-version = re.split(r'[\w-]', gwdatafind_version)[0]
-# The full version, including alpha/beta/rc tags.
-release = gwdatafind_version
-=======
 default_role = 'obj'
 
 # -- theme
->>>>>>> 68380b9 (docs: use furo docs theme)
 
 html_theme = "furo"
 
@@ -49,6 +37,7 @@ html_theme_options = {
     ],
 }
 
+# need fontawesome for the gitlab icon in the footer
 html_css_files = [
     "https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.1.2/css/fontawesome.min.css",
     "https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.1.2/css/solid.min.css",
@@ -104,6 +93,12 @@ napoleon_use_rtype = False
 def _project_git_ref(version, prefix="v"):
     """Returns the git reference for the given full release version.
     """
+    # handle builds in CI
+    if os.getenv("GITLAB_CI"):
+        return os.environ["CI_COMMIT_REF"]
+    if os.getenv("GITHUB_ACTIONS"):
+        return os.environ["GITHUB_SHA"]
+    # otherwise use the project metadata
     _setuptools_scm_version_regex = re.compile(
         r"\+g(\w+)(?:\Z|\.)",
     )
@@ -118,7 +113,7 @@ PROJECT_URL = getenv(
     "CI_PROJECT_URL",
     "https://git.ligo.org/computing/gwdatafind/client",
 )
-PROJECT_BLOB_URL = f"{PROJECT_URL}/-/blob/{PROJECT_GIT_REF}/{PROJECT_PATH.name}"
+PROJECT_BLOB_URL = f"{PROJECT_URL}/blob/{PROJECT_GIT_REF}/{PROJECT_PATH.name}"
 
 
 def linkcode_resolve(domain, info):