Mention igniter in v0.26 Changelog Migration Guide

[maennchen]

Zach built a nice igniter mix migration task. I thought it would be good to mention it in the changelog to make the update simpler for our users.

[coveralls]

Pull Request Test Coverage Report for Build 62116e0691e29f187efaf845d9550362b921caee-PR-397

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

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Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 92.024%

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Totals
Change from base Build 898f7c495d1da6de7bc3d98fbd9578efeca369d8:	0.0%
Covered Lines:	623
Relevant Lines:	677

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💛 - Coveralls