Replace M.A.All meta-package with Microsoft.AspNetCore.App - MD files only

[Rick-Anderson]

currently mentioned in 22 files. This issue is about updating the docs that specifically mention Microsoft.AspNetCore.All

We need to convert a few of these and agree on the language and style of the update.

Updating the samples that use the ALL meta-package is a lower priority. See Update all 2.0 samples to use M.A.App, aka Microsoft.AspNetCore.App #6382

[guardrex]

For reference: aspnet/Announcements#287

[scottaddie]

@guardrex client-side\spa-services.md isn't project.json-based. You can remove that one from your list above, if that's what it's tracking.

[rachelappel]

@guardrex I looked at the environments and error-handling docs and I don't see any references to "Microsoft.AspNetCore.All" in those.

[guardrex]

[2X EDIT 😄] "Replace ALL meta-package with App Microsoft.AspNetCore.App - MD files only" ... I missed the "MD files only" bit. I'm pulling the data for when we have an issue that pertains to samples.

[rachelappel]

Oh geez I forgot to look at the samples and hit just the docs.

[guardrex]

I totally missed what @Rick-Anderson was asking for here. I thought we'd do both ... fix the doc AND fix the sample. My bad. I think the samps will be a different issue. When we set that up tho ... I'll paste that table back in.

[EDIT] As this issue stands, I think only one of us really needs to breeze thru and fix the MD files. Really shouldn't take all that long (guessing).