Add Doxygen ingroup command as a recognised token in CI spellchecker

Author: hugueskamba

tools/test/travis-ci/doxy-spellchecker/spell.sh

@@ -20,6 +20,7 @@ while read file; do
     # matched.
     start_tokens=(  "/@code"
                     "/addtogroup"
+                    "ingroup"
                     "defgroup"
                     "<"
                     "()"
@@ -28,13 +29,15 @@ while read file; do
     formats=(   'strip_between'
                 'strip_between'
                 'strip_line'
+                'strip_line'
                 'strip_between_sameline'
                 'strip_token'
             )
 
     end_tokens=(    "/@endcode"
                     "/\*"
                     ""
+                    ""
                     ">"
                     ""
                )