Gradle getdown release

Create the getdown release channel for Jalview.org
None

Plan branches

Plan Build Completed Tests Reason
bug-JAL-4059_update_swingJS_for_JalviewJS_2_11_2_and_2_11_3 No build history Never built
doc-JAL-4090_Release_2_11_3_0 No build history Never built
merge-JAL-4262+JAL-4265+JAL-4269+JAL-4274+JAL-4277+JAL-4285 No build history Never built