Change naming of zLUX on doc site as appropriate

[nannanli]

We renamed zLUX to Zowe Application Framework and MVD to Zowe Desktop in User Guide. However, in developer tutorials and samples, there are still some occurrences that confuse users.

Feedback from Alex on Zowe #zowe-onboarding channel:
Question on Naming Convention: I see the zowe document and there are many places call individual components as all ‘zowe’ or ‘zowe - something(zowe-cli)’ but zLUX seems like another name there - is there a reason for it? I see zLUX is another name for Zowe Application Framework, but it is being used mixed with Zowe again(i.e. Zowe zLUX). I am sorry if this has already been discussed but I would like to see a common naming convention to each components (server side, client side etc) and show in the beginning of the document

[BrandonJenkins14]

What is the status of this issue @jhenryRocket ? I see you did some work here, shall we close the issue? Thanks!

[jhenryRocket]

Ultimately, I think Alex's idea: "I would like to see a common naming convention to each components (server side, client side etc) and show in the beginning of the document" is a good solution to this issue. Hopefully, this will be the case in a future release. (i.e. we no longer have references to zLUX.) Currently zLUX is used in the codebase.

[BrandonJenkins14]

@AlysonAndresen @jasonenglish2039 Just a reminder that this issue exists - basically using consistent/correct terms throughout doc for things like "Zowe Desktop", formerly MVD.

[jasonenglish2039]

See commit to docs-staging referenced in the last comment in this issue (eb5c418). I searched the doc for instances of "zLUX" and "MVD." Changed "zLUX" to "Zowe Application Server" and "MVD" to "Zowe Desktop."

Note: Most instances of zLUX are in directory names or URLs or code. Those could not be changed obviously.