Update govuk_tech_docs to version 2.0.7

This includes many accessibility fixes and improvements

Gemfile.lock

@@ -44,7 +44,7 @@ GEM
     fast_blank (1.0.0)
     fastimage (2.1.7)
     ffi (1.11.1)
-    govuk_tech_docs (2.0.5)
+    govuk_tech_docs (2.0.7)
       activesupport
       chronic (~> 0.10.2)
       middleman (~> 4.0)
@@ -131,7 +131,7 @@ GEM
       rouge (~> 2.0)
     mini_portile2 (2.4.0)
     minitest (5.12.2)
-    multi_json (1.13.1)
+    multi_json (1.14.1)
     nokogiri (1.10.4)
       mini_portile2 (~> 2.4.0)
     openapi3_parser (0.5.2)
@@ -150,7 +150,7 @@ GEM
     rack (2.0.7)
     rack-livereload (0.3.17)
       rack
-    rake (12.3.3)
+    rake (13.0.0)
     rb-fsevent (0.10.3)
     rb-inotify (0.10.0)
       ffi (~> 1.0)