Explanation:

Box 1; tag
Tagging. Like most VCSs, Get has the ability to tag specific points in a repository's history as being important. Typically, people use this functionality to mark release points (v1.0, v2.0 and so on).
Box 2: -a
Creating an annotated tag in Get is simple. The easiest way is to specify -a when you run the tag command:
Example:
$ get tag -a v1.4 -m "my version 1.4"
Box3: -m
Reference:
https://git-scm.com/book/en/v2/Git-Basics-Tagging

Explanation:

Box 1: Progressive exposure
Continuous Delivery may sequence multiple deployment "rings" for progressive exposure (also known as
"controlling the blast radius"). Progressive exposure groups users who get to try new releases tomonitor their experience in "rings." The first deployment ring is often a "canary" used to test new versions in production before a broader rollout. CD automates deployment from one ring to the next and may optionally depend on an approval step, in whicha decision maker signs off on the changes electronically. CD may create an auditable record of the approval in order to satisfy regulatory procedures or other control objectives.

Box 2: Feature flags
Feature flags support a customer-first DevOps mindset, to enable (expose) and disable (hide) features in a solution, even before they are complete and ready for release.
Box 3: Blue/green
Blue/green deployments which means that instead of replacing the previous version (here we refer to this version as blue), we bring up the new version (here referred to as the green version) next to the existing version, but not expose it to the actual users right away. On the condition of having successfully validated that the green version works correctly, we will promote this version to the public version by changing the routing configuration without downtime. If something is wrong with the green version we can revert back without users every noticing interruptions.
Reference:
https://docs.microsoft.com/en-us/azure/devops/learn/what-is-continuous-delivery
https://docs.microsoft.com/en-us/azure/devops/migrate/phase-features-with-feature-flags
https://medium.com/@denniszielke/continuous-kubernetes-blue-green-deployments-on-azure-using-nginx- appgateway-or-trafficmanager-4490bce29cb

A) Jekyll is a static site generator that can be used to generate a static website from Markdown files stored in a GitHub repository. Jekyll supports the use of Markdown for writing documentation, and it can automatically recompile the website whenever changes are made to the documentation.
E) Doc FX is another tool that can be used to compile a static website from Markdown files stored in a GitHub repository. It is an open-source tool that can be used to generate API documentation, reference documentation, and other types of documentation from source code and other files. Doc FX supports the use of Markdown for writing documentation and it can automatically recompile the website whenever changes are made to the documentation.