Mention OMERO for SciJava install method

Clarify manual download instructions for OMERO and update Fiji requirements.

Author: ehrenfeu

README.md

@@ -58,18 +58,20 @@ following necessary update sites for this package.
 The **`IMCF Uni Basel`** update-site will always provide the latest compatible
 combination of *official* `.jar` files to use this package.
 
-### Manual Downloads
+### Manual Downloads for OMERO
 
-In addition to the update sites, two manual downloads concerning OMERO are necessary:
+In addition to the update sites, two manual downloads concerning OMERO are
+necessary:
 
 - [simple-omero-client]
 - [omero-insight]
 
 ### 🏗 Alternative: SciJava Maven Package 👷
 
 💡 **IMPORTANT:** 💡 same as for the *default* installation previously
-described, you will need to enable **all Update Sites listed above** in your
-Fiji as well when using the method described here!
+described, you will need to enable **all Update Sites listed above** (and
+obviously the respective OMERO downloads) in your Fiji as well when using the
+method described here!
 
 The most up-to-date `.jar` (or any other published version, including
 pre-releases) for this package can be always found on the [Scijava Maven