More comprehensive CLI dev tutorial

[BrandonJenkins14]

@tucker01, @zFernand0 just creating this issue to note our idea of improving the CLI dev tutorials.

As a CLI plug-in developer, I want to read a single document that introduces me to the development resources and walks me through the major steps from new idea to built and delivered plug-in. Current tutorials focus on adding commands and creating your first standalone plug-in.

We could improve by adding information about:

• Planning your plug-in (considering cli use cases, command naming, dev tools and skills that you should already have before getting started, etc...)
• Information about developing the API portion of code.
• When, how, and why to submit for Zowe Conformance
• Information about getting your plug-in into the Zowe Jenkins builds, other administrative tasks to publish and advertise your plug-in.
• Advice for maintaining your plug-in as part of a community.

[BrandonJenkins14]

Consider: We have 2 versions of the tutorial, one in "Stable" and one in "Active Development" doc. Currently, the only difference is which branch is to be cloned and whether to use @brightside or @zowe dependencies.

We might want to explain developing for both versions in a more linear way, rather than the current setup where you follow one version of the tutorial then the other. Potentially confusing.

[zFernand0]

@JamesBauman, @BrandonJenkins14, How about migrating/merging the tutorial with the corresponding branches (on the sample-plugin) for Active Development (master) and Stable (lts-incremental)?