Docs: plugin migration guide 7.0.0 to 8.0.0 (#38911)
Docs: plugin migration guide 7.0.0 to 8.0.0 (#38911)

* restructuring to new storybook inspired structure.

* added instructions on how to handle breaking changes in the legend.

* start adding migration steps for 7 -> 8

* added information about the data frame format changes.

* added plugin.json changes.

* added emotion 11 imports.

* added information about theme v1 being deprecated.

* added steps for backend plugin migration.

* added reference to the migrate hooks v6 -> v7.

* docs(pluginmigration): introduce getColorForTheme changes

* Update docs/sources/developers/plugins/migration-guide.md

Co-authored-by: Levente Balogh <f27809d64915dcf27e873bedfefac659fb5e4ea8@gmail.com>

* Update docs/sources/developers/plugins/migration-guide.md

Co-authored-by: Jack Westbrook <b479ec85b833e80220570fef0538b9a3f5e71fcf@gmail.com>

* Update docs/sources/developers/plugins/migration-guide.md

Co-authored-by: Levente Balogh <f27809d64915dcf27e873bedfefac659fb5e4ea8@gmail.com>

* Update docs/sources/developers/plugins/migration-guide.md

Co-authored-by: Levente Balogh <f27809d64915dcf27e873bedfefac659fb5e4ea8@gmail.com>

* Update docs/sources/developers/plugins/migration-guide.md

Co-authored-by: Levente Balogh <f27809d64915dcf27e873bedfefac659fb5e4ea8@gmail.com>

* docs(migration-guide): introduce useStyles to v8 deprecation notes

* Apply suggestions from code review

Co-authored-by: achatterjee-grafana <5ed7255a3b2540ccce8f5b30c47e4a93678b261d@users.noreply.github.com>

* Update docs/sources/developers/plugins/migration-guide.md

Co-authored-by: achatterjee-grafana <5ed7255a3b2540ccce8f5b30c47e4a93678b261d@users.noreply.github.com>

* Update docs/sources/developers/plugins/migration-guide.md

Co-authored-by: achatterjee-grafana <5ed7255a3b2540ccce8f5b30c47e4a93678b261d@users.noreply.github.com>

* Update docs/sources/developers/plugins/migration-guide.md

Co-authored-by: achatterjee-grafana <5ed7255a3b2540ccce8f5b30c47e4a93678b261d@users.noreply.github.com>

* Update docs/sources/developers/plugins/migration-guide.md

Co-authored-by: achatterjee-grafana <5ed7255a3b2540ccce8f5b30c47e4a93678b261d@users.noreply.github.com>

* suggestion from review.

* Update docs/sources/developers/plugins/migration-guide.md

Co-authored-by: achatterjee-grafana <5ed7255a3b2540ccce8f5b30c47e4a93678b261d@users.noreply.github.com>

* docs(Migration Guide): update the example for `grafanaDependency`

* docs(Migration Guide): remove the time-series migration part for now

* Update docs/sources/developers/plugins/migration-guide.md

Co-authored-by: Will Browne <bad36ff42e1757bffd31c0fdc6e4abf62945bf9c@users.noreply.github.com>

* Update docs/sources/developers/plugins/migration-guide.md

Co-authored-by: Ursula Kallio <6abe1d214fe6673fbe73ed14f2a01e531675b817@users.noreply.github.com>

* docs(Migration Guide): update wording about plugin signing

* Update docs/sources/developers/plugins/migration-guide.md

Co-authored-by: achatterjee-grafana <5ed7255a3b2540ccce8f5b30c47e4a93678b261d@users.noreply.github.com>

* Update docs/sources/developers/plugins/migration-guide.md

Co-authored-by: achatterjee-grafana <5ed7255a3b2540ccce8f5b30c47e4a93678b261d@users.noreply.github.com>

* Update docs/sources/developers/plugins/migration-guide.md

Co-authored-by: achatterjee-grafana <5ed7255a3b2540ccce8f5b30c47e4a93678b261d@users.noreply.github.com>

Co-authored-by: Jack Westbrook <b479ec85b833e80220570fef0538b9a3f5e71fcf@gmail.com>
Co-authored-by: Levente Balogh <f27809d64915dcf27e873bedfefac659fb5e4ea8@gmail.com>
Co-authored-by: achatterjee-grafana <5ed7255a3b2540ccce8f5b30c47e4a93678b261d@users.noreply.github.com>
Co-authored-by: Will Browne <bad36ff42e1757bffd31c0fdc6e4abf62945bf9c@users.noreply.github.com>
Co-authored-by: Ursula Kallio <6abe1d214fe6673fbe73ed14f2a01e531675b817@users.noreply.github.com>
grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana