Fix typo in PR template

.github/PULL_REQUEST_TEMPLATE

@@ -1,7 +1,7 @@
 To ease the review process, please consider the following before to open the pull request:
 - is your code well commented?
 - did you update the relevant README(s)? See e.g. https://github.com/key4hep/k4geo/blob/main/detector/calorimeter/README.md or https://github.com/key4hep/k4geo/blob/main/FCCee/IDEA/compact/README.md
-- if you added some code, is is covered by tests? See https://github.com/key4hep/k4geo/blob/main/lcgeoTests/CMakeLists.txt
+- if you added some code, is it covered by tests? See https://github.com/key4hep/k4geo/blob/main/lcgeoTests/CMakeLists.txt
 - is your PR branch up to date with origin 'main'?
 - are you not adding/modifying files that should not have been added/modified (or at least, not in this PR)?
 
@@ -13,3 +13,4 @@ BEGINRELEASENOTES
 - ...
 
 ENDRELEASENOTES
+