Add support for Paperless AI API token and environment variables

This commit introduces several significant changes to the Paperless AI
Helm chart:

- Updated the version from 0.5.0 to 0.6.0 in `Chart.yaml` to reflect
  the new additions.
- Added a new template `paperlessApiSecret.yaml` to define a Kubernetes
  Secret for the Paperless API token. This allows secure storage of the
  API token, which is now a required value for communication with the
  Paperless application.
- Introduced a new function in `_helpers.tpl` called `generateEnv`
  that dynamically generates a `.env` file from various configuration
  values in `values.yaml`. This includes settings for the Paperless API
  URL, AI provider, tagging options, scanning intervals, and more.
- Updated `values.yaml` to include necessary configurations for the
  Paperless API, OpenAI, and other related settings, making it easier
  for users to configure the chart per their requirements.
- Adjusted resource limits and initial probe delays for improved
  performance and quicker health checks.

These enhancements provide better configurability and facilitate
secure management of sensitive credentials, thereby improving user
experience and application reliability.

charts/paperless-ai/Chart.yaml

@@ -1,7 +1,7 @@
 apiVersion: v2
 name: paperless-ai
 description: Ein Helm Chart für Paperless AI, basierend auf der Docker Compose Konfiguration.
-version: 0.5.0
+version: 0.6.0
 appVersion: 3.0.7
 keywords:
   - paperless-ai