docs(techniques/mvc): introduce @WithAlias() decorator

[sjones6]

Documents the @WithAlias() decorator and getUrl helper introduced in PR nestjs/nest#5117

PR Checklist

Please check if your PR fulfills the following requirements:

• [X] The commit message follows our guidelines: https://github.com/nestjs/docs.nestjs.com/blob/master/CONTRIBUTING.md

PR Type

What kind of change does this PR introduce?

[ ] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[x] Other... Please describe: docs

What is the current behavior?

Issue Number: See issue nestjs/nest#5117 and PR nestjs/nest#3743.

What is the new behavior?

Adds documentation for @WithAlias() decorator and getUrl() helper.

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information

[RobertAKARobin]

What would it take to get this merged? I'd really like this feature.

[johannesschobel]

The feature is available @RobertAKARobin , this is just the documentation.

[matulek]

The feature is available @RobertAKARobin , this is just the documentation.

@johannesschobel - no, it's not, the PR is still open: https://github.com/nestjs/nest/pull/5117

[johannesschobel]

i am sorry, i must have missed that.

[AeroNotix]

Did this end up going any where?

[marcelobrk]

What happened to that PR?