chore(deps): update flutter_markdown to ^0.7.0 #116

Job	Run time
flutter-test-analyze / Format	36s
flutter-test-analyze / Test	1m 11s
flutter-test-analyze / Analyze	1m 10s
flutter-build / WEB	6s
flutter-build / Android (apk)	6m 17s
flutter-build / iOS	9s
	9m 29s

Provide feedback