better perfective head labelling on verb tree

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@lingdocs/pashto-inflector",
-  "version": "3.1.8",
+  "version": "3.1.9",
   "author": "lingdocs.com",
   "description": "A Pashto inflection and verb conjugation engine, inculding React components for displaying Pashto text, inflections, and conjugations",
   "homepage": "https://verbs.lingdocs.com",

src/components/verb-info/VerbInfo.tsx

@@ -102,7 +102,7 @@ export function RootsAndStems({ textOptions, info, hidePastParticiple, highlight
                                         className="btn btn-sm btn-outline-secondary"
                                         onClick={() => setSplit(!split)}
                                     >
-                                        split
+                                        {split ? "join" : "split"} head
                                     </button>
                                 </div>}
                             </div>