Update Docker Quickstart

[alexfornuto]

Summary

This update simplifies the quickstart process by assuming a local test environment without a TLS solution or a FQDN

Additionally, this PR expands the Docs site with the markdown-it-includes plugin, allowing us to single-source content we want to include in multiple pages.

Checklist

• reference any related issues
• updated docs
• updated unit tests
• updated UPGRADING.md
• add appropriate tag (improvement / bug / etc)
• ready for review

[codeclimate]

Code Climate has analyzed commit 203280d and detected 0 issues on this pull request.

View more on Code Climate.

[coveralls]

Coverage increased (+0.1%) to 64.387% when pulling 203280d on docs/quickstart-update into 6a69d39 on master.

[backport-actions-token]

The backport to 0-15-0 failed:

The process '/usr/bin/git' failed with exit code 1

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-0-15-0 0-15-0
# Navigate to the new working tree
cd .worktrees/backport-0-15-0
# Create a new branch
git switch --create backport-2482-to-0-15-0
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick --mainline 1 65760a9f707dec5986297d476ad56101ea78ed99
# Push it to GitHub
git push --set-upstream origin backport-2482-to-0-15-0
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-0-15-0

Then, create a pull request where the base branch is 0-15-0 and the compare/head branch is backport-2482-to-0-15-0.

[backport-actions-token]

The backport to 0-15-0 failed:

The process '/usr/bin/git' failed with exit code 1

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-0-15-0 0-15-0
# Navigate to the new working tree
cd .worktrees/backport-0-15-0
# Create a new branch
git switch --create backport-2482-to-0-15-0
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick --mainline 1 65760a9f707dec5986297d476ad56101ea78ed99
# Push it to GitHub
git push --set-upstream origin backport-2482-to-0-15-0
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-0-15-0

Then, create a pull request where the base branch is 0-15-0 and the compare/head branch is backport-2482-to-0-15-0.