[DOC] Update codecov instructions

Author: eseiler

.github/workflows/initialise.yml

@@ -36,6 +36,7 @@ jobs:
 
           sed -i 's/# SeqAn App Template/# ${{ github.event.repository.name }}/' README.md
           sed -i 's/App-Template%20CI/${{ github.event.repository.name }}%20CI/g' README.md
+          sed -i 's@https://app.codecov.io/gh/seqan@https://app.codecov.io/gh/${{ github.repository_owner }}@g' README.md
           sed -i '/<!-- InitDelete -->/,/<!-- DeleteInit -->/d' README.md
 
           git checkout test/data/datasources.cmake

README.md

@@ -98,7 +98,9 @@ The instructions below are for the template repository and will not work for you
 
 1. Go to https://codecov.io/gh/seqan/app-template.
 2. Sign in with your GitHub account.
-3. Go to https://app.codecov.io/gh/seqan/app-template/config/general.
+3. Go to https://app.codecov.io/gh/seqan/app-template/config/general.<br>
+   If the repository cannot be found, go to https://app.codecov.io/gh/seqan and click `Resync`.<br>
+   Then try again.
 4. Copy the `Repository Upload Token`.
 5. Go to https://github.com/seqan/app-template/settings/secrets/actions.
 6. Add a `New repository secret` with the name `CODECOV_TOKEN` and the value of the `Repository Upload Token`.