[BUG] imagePullSecrets missing in template, documented in values.yaml

**Describe the bug**
According to the values.yaml an imagePullSecret can be specified.
This is, however, missing in the template of the deployment.

**To Reproduce**
Steps to reproduce the behavior:
1. Add imagePullSecret to values.yaml
2. Template the charts

**Expected behavior**
imagePullSecrets should be included in the template

**Environment (please complete the following information):**
- Version-Checker Charts: v0.11.0

**Additional context**
Let me know if I should directly open a PR for this