Review 'Test documentation changes' page

[jdbaldry]

• Use semantic line breaks.
• Avoid passive voice
• Clarify that the note only refers to Grafana tutorials

Closes https://github.com/grafana/writers-toolkit/issues/680

[github-actions[bot]]

Readability report

File	AutomatedReadability	ColemanLiau	FleschKincaid	FleschReadingEase	GunningFog	LIX	SMOG
docs/sources/review/test-documentation-changes/index.md	$${7.01\space\color{red}(Δ+0.03)}$$	$${10.32\space\color{red}(Δ+0.03)}$$	$${8.62\space\color{red}(Δ+0.07)}$$	$${51.97\space\color{red}(Δ-0.55)}$$	$${10.53\space\color{red}(Δ+0.10)}$$	$${41.10\space\color{red}(Δ+0.25)}$$	$${11.18\space\color{red}(Δ+0.05)}$$

View metric targets

| Metric | Range | Ideal score | | --- | --- | --- | | [AutomatedReadability](https://en.wikipedia.org/wiki/Automated_readability_index) | 6 (very easy read) to 14 (extremely difficult read) | 8 or less | | [ColemanLiau](https://en.wikipedia.org/wiki/Coleman%E2%80%93Liau_index) | 6 (very easy read) to 17 (extremely difficult read) | 9 or less | | [FleschKincaid](https://en.wikipedia.org/wiki/Flesch%E2%80%93Kincaid_readability_tests) | 6 (very easy read) to 17 (extremely difficult read) | 8 or less | | [FleschReadingEase](https://en.wikipedia.org/wiki/Flesch%E2%80%93Kincaid_readability_tests) | 100 (very easy read) to 0 (extremely difficult read) | 70 or more | | [GunningFog](https://en.wikipedia.org/wiki/Gunning_fog_index) | 6 (very easy read) to 17 (extremely difficult read) | 10 or less | | [LIX](https://en.wikipedia.org/wiki/Lix_(readability_test)) | 20 (very easy read) to 60+ (extremely difficult read) | 35 or less | | [SMOG](https://en.wikipedia.org/wiki/SMOG) | 6 (very easy read) to 17 (extremely difficult read) | 10 or less |