Tweak changeset documentation

Signed-off-by: Andrew Shirley <andrew.shirley@sainsburys.co.uk>
Signed-off-by: blam <ben@blam.sh>

.changeset/good-hornets-hunt.md

@@ -1,5 +1,5 @@
 ---
-'@backstage/plugin-jenkins': major
+'@backstage/plugin-jenkins': minor
 ---
 
 ## Extract an entity-oriented Jenkins Backend

.changeset/light-frogs-prove.md

@@ -1,5 +1,4 @@
 ---
-'example-backend': patch
 '@backstage/plugin-jenkins-backend': patch
 ---