extensions: Ensure make uses tab instead of space.

[lance]

This change addresses the following issues:

#6447
#4815

It was not clear to me how to write an automated test for this change. All testing was done manually. When editing a Makefile, now the default is to use tabs instead of spaces. Switching to another file/type, and then back to the Makefile does not alter this behavior. Quitting and restarting the editor also does not alter this behavior. If an automated test is required, please point me to an example so that I can replicate it.

[mention-bot]

By analyzing the blame information on this pull request, we identified @egamma to be a potential reviewer

[msftclas]

Hi @lance, I'm your friendly neighborhood Microsoft Pull Request Bot (You can call me MSBOT). Thanks for your contribution!

This seems like a small (but important) contribution, so no Contribution License Agreement is required at this point. Real humans will now evaluate your PR.

TTYL, MSBOT;

[alexdima]

@lance This proposed change has no effect. Here is where the language configuration is handled. We currently do not support mode specific settings so wiring this in might be tricky.

[lance]

@alexandrudima ok - I remain confused about the behavior I am seeing. The behavior noted in the two issues I reference here does not occur for me with these changes. But it's completely unclear why to me now. Hmm.

[alexdima]

I think this setting might make things unexpected:

// When opening a file, `editor.tabSize` and `editor.insertSpaces` will be detected based on the file contents.
    "editor.detectIndentation": true,

When editor.detectIndentation is true (the default), the tab settings will be guessed from the opened file (i.e. mostly spaces vs mostly tabs, etc.). Sometimes, (e.g. the opened file is empty), guessing is not possible and the settings defined via editor.tabSize and editor.insertSpaces will be used.

[markadrake]

Edit I take my request back. Really this is my fault for not reading the entirety of the settings document. I'm more upset with myself for experiencing this exact issue for weeks and not thinking it had anything to do with another setting. :) Thanks for clearing up my issue though.