Make links clickable

Issue #60.

package.json

@@ -15,6 +15,7 @@
     "intersection-observer": "^0.11.0",
     "js-sha256": "^0.9.0",
     "json-web-key": "^0.4.0",
+    "linkifyjs": "^2.1.9",
     "material-design-icons-iconfont": "^5.0.1",
     "matrix-js-sdk": "^9.4.1",
     "mic-recorder-to-mp3": "^2.2.2",
@@ -27,6 +28,7 @@
     "vue-clipboard2": "^0.3.1",
     "vue-resize": "^0.5.0",
     "vue-router": "^3.2.0",
+    "vue-sanitize": "^0.2.1",
     "vuetify": "^2.2.11",
     "vuex": "^3.5.1",
     "vuex-persist": "^3.1.3"