Instructions for integrating with a basic CodeQL workflow should be updated for java-kotlin name

[daniel-beck]

The instructions in this repo's readme assume that java is one of the matrix.languages in

dismiss-alerts/README.md

Line 71 in 9e8b8a1

sarif-file: sarif-results/${{ matrix.language }}.sarif

and

dismiss-alerts/README.md

Line 51 in 9e8b8a1

packs: "codeql/${{ matrix.language }}-queries:AlertSuppression.ql"

Since actions/starter-workflows#2177 and github/codeql-action#1883 it seems that java-kotlin is the canonical language name. In particular the starter workflow instructions seem to clash with what this action expects.