chore: fix stale metadata and README wording

- .abapgit.xml: a2UI5-selection-screen -> selection-screen
- src/package.devc.xml: describe the package as
  abap2UI5 - selection screen
- README: SAP NetWeaver instead of R/3 NetWeaver

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014yy9ZjmgSF6UabP6mqfSLz

Author: claude

.abapgit.xml

@@ -2,7 +2,7 @@
 <asx:abap xmlns:asx="http://www.sap.com/abapxml" version="1.0">
  <asx:values>
   <DATA>
-   <NAME>a2UI5-selection-screen</NAME>
+   <NAME>selection-screen</NAME>
    <MASTER_LANGUAGE>E</MASTER_LANGUAGE>
    <STARTING_FOLDER>/src/</STARTING_FOLDER>
    <FOLDER_LOGIC>PREFIX</FOLDER_LOGIC>

README.md

@@ -12,7 +12,7 @@
 #### Compatibility
 * S/4 Public Cloud and BTP ABAP Environment (ABAP for Cloud)
 * S/4 Private Cloud or On-Premise (ABAP for Cloud, Standard ABAP)
-* R/3 NetWeaver AS ABAP 7.50 or higher (Standard ABAP)
+* SAP NetWeaver AS ABAP 7.50 or higher (Standard ABAP)
 
 #### Dependencies
 * [abap2UI5](https://github.com/abap2UI5/abap2UI5)

src/package.devc.xml

@@ -3,7 +3,7 @@
  <asx:abap xmlns:asx="http://www.sap.com/abapxml" version="1.0">
   <asx:values>
    <DEVC>
-    <CTEXT>a2UI5-selection-screen</CTEXT>
+    <CTEXT>abap2UI5 - selection screen</CTEXT>
    </DEVC>
   </asx:values>
  </asx:abap>