Change GitHub organisation from aimakerspace to aisingapore.

Add details.

Add more stages and rules for GitLab CICD pipelines.

Correct data preprocessing commands for data preparation Polyaxonfile.

Major commit for the following changes:

- Added banner images for some major headings.
- Added input parameters to Polyaxonfiles to define Docker images on the fly.
- Detailed usage of gsutil cp for retrieval of raw sample data for guide's problem statement.
- Changed some heading levels.
- Shift and redefine data storage and versioning stage.

Added/made revisions for the following:

- Python script, Dockerfile and accompanying files for batch inferencing
- Revised .dockerignore file
- Added guides for batch inferencing, Sphinx docs
- Minor omissions for some Python scripts
- Removed other stages for GitLab CI/CD except for pages-deploy
- Replaced usage of cookiecutter CLI with cruft CLI

Update README guide with sections for deployment of models with FastA…

…PI as well as addition of accompanying image assets.