doc: add link to INSTALL.md so people can actually click it

Author: pbek

solid/appinfo/info.xml

@@ -9,7 +9,7 @@
 This app gives every user on the server a Solid pod storage space and a corresponding WebID URL.
 It supports the webid-oidc-dpop-pkce login flow to connect to a Solid App with your Nextcloud User.
 When you do this, the Solid App can store data in your Nextcloud account through the Solid protocol.
-IMPORTANT: See https://github.com/pdsinterop/solid-nextcloud/blob/main/INSTALL.md for additional install instructions!
+IMPORTANT: See [INSTALL.md](https://github.com/pdsinterop/solid-nextcloud/blob/main/INSTALL.md) for additional install instructions!
 ]]></description>
     <version>0.7.2</version>
     <licence>agpl</licence>