Bump rexml from 3.3.2 to 3.3.3 in /docs in the bundler group (#1939)

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

docs/Gemfile.lock

@@ -250,7 +250,7 @@ GEM
     rb-fsevent (0.11.0)
     rb-inotify (0.10.1)
       ffi (~> 1.0)
-    rexml (3.3.2)
+    rexml (3.3.3)
       strscan
     rouge (3.26.0)
     ruby2_keywords (0.0.5)