Adds Contributor Documentation

[swainn]

Description

This pull request adds documentation for contributors to Tethys Platform.

Draft:

• Introduction / Landing Page (contribute.rst)
• Contributing Code Overview (contribute/code.rst)
  • Getting Started Tutorial (contribute/getting_started.rst)
  • Setting up a development environment (contribute/dev_environment.rst)
  • Development Process (contribute/development_process.rst)
    • Testing (contribute/testing.rst)
  • Managing Issues (contribute/issues.rst)
  • Coding Principles (contribute/coding_principles.rst)
    • Tethys Core (contribute/coding_principles/core.rst)
    • Tethys CLI (contribute/coding_principles/cli.rst)
    • Tethys Compute (contribute/coding_principles/compute.rst)
    • Tethys Gizmos (contribute/coding_principles/gizmos.rst)
    • Tethys Layouts (contribute/coding_principles/layouts.rst)
    • Tethys Portal (contribute/coding_principles/tethys_portal.rst)
    • Code Organization (contribute/coding_principles/organization.rst)
  • Maintaining Dependencies (contribute/dependencies.rst)
  • Deploying New Versions (contribute/deploying_tethys.rst)
• Contributing Documentation (contribute/documentation.rst)
  • Building the Docs
  • Source Files
  • Guidelines
  • Demo
  • I18n
• Supporting the Community (contribute/community.rst)

Reviewed:

• Introduction / Landing Page (contribute.rst)
• Contributing Code Overview (contribute/code.rst)
  • Getting Started Tutorial (contribute/getting_started.rst)
  • Setting up a development environment (contribute/dev_environment.rst)
  • Development Process (contribute/development_process.rst)
    • Testing (contribute/testing.rst)
  • Coding Principles (contribute/coding_principles.rst)
    • Tethys Core (contribute/coding_principles/core.rst)
    • Tethys CLI (contribute/coding_principles/cli.rst)
    • Tethys Compute (contribute/coding_principles/compute.rst)
    • Tethys Gizmos (contribute/coding_principles/gizmos.rst)
    • Tethys Layouts (contribute/coding_principles/layouts.rst)
    • Tethys Portal (contribute/coding_principles/tethys_portal.rst)
    • Code Organization (contribute/coding_principles/organization.rst)
  • Maintaining Dependencies (contribute/dependencies.rst)
  • Deploying New Versions (contribute/deploying_tethys.rst)
• Contributing Documentation (contribute/documentation.rst)
  • Building the Docs
  • Source Files
  • Guidelines
  • Demo
  • I18n
• Supporting the Community (contribute/community.rst)

[coveralls]

coverage: 99.973%. remained the same
when pulling 37ad9e1 on contributor-documentation
into e95effb on main.