doc: Update doc link for database protocol adapter (#1051)

Author: caoccao

hivemq-edge/src/main/resources/hivemq-edge-configuration.json

@@ -214,7 +214,7 @@
       "description" : "Connects HiveMQ Edge to existing databases (MySQL, PostgresSQL or MS SQL).",
       "author" : "HiveMQ",
       "documentationLink" : {
-        "url" : "https://docs.hivemq.com/hivemq-edge/protocol-adapters.html",
+        "url" : "https://docs.hivemq.com/hivemq-edge/protocol-adapters.html#databases-protocol-adapter",
         "external" : true
       },
       "provisioningLink" : {

modules/hivemq-edge-module-databases/src/main/java/com/hivemq/edge/adapters/databases/DatabasesProtocolAdapterInformation.java

@@ -72,7 +72,7 @@ protected DatabasesProtocolAdapterInformation() {
     public @NotNull String getUrl() {
         // this url will be displayed in the ui as a link to further documentation on this protocol adapter.
         // e.g. this could be a link to the source code and a readme
-        return "TO BE DEFINED";
+        return "https://docs.hivemq.com/hivemq-edge/protocol-adapters.html#databases-protocol-adapter";
     }
 
     @Override