Update TROUBLESHOOTING.md to reflect Builder methods name changes

[DivineGod]

Updates to the names of methods on the Builder merged in PR #113 missed updating the TROUBLESHOOTING.md file

[rfuest]

Good catch!

There's another part of the document that hasn't been updated in line 26, where Builder::ili9486_rgb666(di) instead of the current Builder::new(ILI9486Rgb666, di). Could you also fix that while you are at it?

@almindor: I had previously suggested to move the troubleshooting doc into the rustdoc docs (#76). My primary concern in that issue was that the troubleshooting doc isn't versioned and that older versions on docs.rs won't link to the correct version of the troubleshooting doc. But this issue shows that there would be another benefit of integrating the troubleshooting guide into the rustdoc docs, which is that we could run doc tests to make sure the code examples remain valid. What is your opinion on this?

[DivineGod]

There's another part of the document that hasn't been updated in line 26, where Builder::ili9486_rgb666(di) instead of the current Builder::new(ILI9486Rgb666, di). Could you also fix that while you are at it?

Done

[rfuest]

Thanks!