Issue 385 mkdocs doc

[srggrs]

This is the first version of the public website with documentation, tips and all the useful info for this pipeline.

Points:

• You can check the actual website info on https://vast-survey.org/vast-pipeline/.
• I linked some of the files inside the docs folder in this way:

  architecture
  changelog.md -> ../CHANGELOG.md
  code_of_conduct.md -> ../CODE_OF_CONDUCT.md
  developing
  img
  license.md -> ../LICENSE.txt
  quickstart
  README.md -> ../README.md
  theme
  usage

  so that when we modify the CHANGELOG and the others, the website will reflect those changes.
• if you are wondering why the images and gif on the README are not rendering in the website, is because the repo is private, but they render on the branch in GitHub.

I was also wondering if we should re-organise the repo content by moving all the "app" code into vast_pipeline_app:

vast_pipeline_app
├── gulpfile.js
├── init-tools
├── manage.py
├── package.json
├── package-lock.json
├── scss
├── static
├── staticfiles
├── templates
├── vast_pipeline
└── webinterface

Close #385, close #324, close #22, close #355
Not sure about this #141 @ajstewart @marxide ?

[ajstewart]

Mostly just text fixes.

[ajstewart]

Actually - I realised the changelog has not been updated.

[srggrs]

Actually - I realised the changelog has not been updated.

This is ready to be reviewed @ajstewart

[ajstewart]

Has the CHANGELOG.md been updated with the changes this PR makes? I don't see any edits to it.

[srggrs]

Has the CHANGELOG.md been updated with the changes this PR makes? I don't see any edits to it.

done

[ajstewart]

I'm happy for it to be merged.