fix(docs): fix build errors for latexpdf

Fixes errors encountered when handling SVG graphics, unicode characters,
and deeply nested lists (i.e. in the change log) with the `latexpdf`
docs build. Adds `sphinxcontrib-svg2pdfconverter` to allow embedding SVG
images into PDF files; changes the LaTeX engine to XeLaTex to provide
wider support for unicode characters (see [1] for more details); and
increases the maximum list depth.

[1] https://www.sphinx-doc.org/en/master/usage/configuration.html#confval-latex_engine

Change-Id: I2ee265d301f6822bae7aa6dfa3a8bfcf070076d3
Signed-off-by: Harrison Mutai <harrison.mutai@arm.com>
diff --git a/.versionrc.js b/.versionrc.js
index 4e9c71f..3a21ded 100644
--- a/.versionrc.js
+++ b/.versionrc.js
@@ -101,6 +101,25 @@
             "type": "json"
         },
         {
+            "filename": "docs/conf.py",
+            "updater": {
+                "readVersion": function (contents) {
+                    const _ver = contents.match(/version\s=.*"(\d)\.(\d)\.(\d)/);
+
+                    return `${_ver[1]}.${_ver[2]}.${_ver[2]}`;
+                },
+
+                "writeVersion": function (contents, version) {
+                    const _ver = 'version = "' + version + '"'
+                    const _rel = 'release = "' + version + '"'
+
+                    contents = contents.replace(/^(version\s=\s")((\d).?)*$/m, _ver)
+                    contents = contents.replace(/^(release\s=\s")((\d).?)*$/m, _rel)
+                    return contents
+                }
+            },
+        },
+        {
             "filename": "tools/conventional-changelog-tf-a/package.json",
             "type": "json"
         },