Capitalize React concepts in docs

Summary

We should be capitalizing proper React concepts in the docs. This was flagged by @samselikoff here and I took a first pass at correct Effects, Hooks, and Transitions in https://github.com/reactjs/react.dev/pull/6712.

Remaining items

The remaining items are:

• Components (In progress: https://github.com/reactjs/react.dev/pull/6717)
• State (In progress: https://github.com/reactjs/react.dev/pull/6720)
• Actions
• Context (In progress: https://github.com/reactjs/react.dev/pull/6718)
• Suspense
• Error Boundaries (In Progress: https://github.com/reactjs/react.dev/pull/6719)
• ... more?

Submitting a PR

• Please do not ask to take an item, just submit a PR. If multiple people submit the same PR, I'll add co-author credit to the commit.

• Only submit one PR per concept

• When you submit a PR, please try and cover all usages in all the docs, on all pages excluding the blog and community pages.

• Avoid fixing one or two instances and favor full coverage to minimize the number of PRs and reviews.

Note that headings like {/* usestate */} must stay lower case, so a find and replace won't work.

Style Guide

• Capitalize React-specific concepts: Capitalize the names of React concepts and features when referring to them specifically.
• Lowercase all others: Use lowercase when these words are used in a general context or referring to their general computing or programming meaning.

Guidelines for Specific Terms

Components

• Capitalize when referring to React Components
  • ❌ Incorrect: "functional components are a core concept in React."
  • ✅ Correct: "Functional Components are a core concept in React."
• Use lowercase when discussing components in a general programming or descriptive sense
  • ❌ Incorrect: "Components should manage their own State."
  • ✅ Correct: "components should manage their own state."

State

• Capitalize when discussing React State in the context of the React system
  • ❌ Incorrect: "Create dynamic and interactive Components with state."
  • ✅ Correct: "Create dynamic and interactive Components with State."
• Use lowercase for the general concept of state
  • ❌ Incorrect: "When a component's State changes, it re-renders."
  • ✅ Correct: "When a component's state changes, it re-renders."

Effects

• Capitalize when referring to Effects used via hooks like useEffect
  • ❌ Incorrect: "Use effects to perform side effects in function components."
  • ✅ Correct: "Use Effects to perform side effects in function components."
• Use lowercase for general references to effects or side effects in programming
  • ❌ Incorrect: "Effects let you perform side Effects in function components."
  • ✅ Correct: "Effects let you perform side effects in Function Components."

Transitions

• Capitalize when discussing the specific Transition feature ("use Transitions to defer updates").
  • ❌ Incorrect: "use transitions to defer updates"
  • ✅ Correct: "use Transitions to defer updates"
• Use lowercase when referring to the general concept of transitions in UI/UX ("transition animations").
  • ❌ Incorrect: You can also add a CSS Transition to delay dimming
  • ✅ Correct: You can also add a CSS transition to delay dimming

Context

• Capitalize when discussing the specific Context feature ("use Context to share data").
  • ❌ Incorrect: "use context to share data between components"
  • ✅ Correct: "use Context to share data between Components"
• Use lowercase when the word "context" refers to the general concept of context (understand the context)
  • ❌ Incorrect: "understand the Context it's running in"
  • ✅ Correct: "understand the context it's running in"

Beginne mit dem Styleguide des Issues und durchsuche dann alle Dokumentationsseiten nach einem verbleibenden Konzept wie Actions oder Suspense, wobei Blog- und Community-Seiten ausgeschlossen werden. Überprüfe jede Verwendung im Kontext, da allgemeine Programmierbegriffe und Überschriften wie {/* usestate */} kleingeschrieben bleiben. Fertig bedeutet, dass ein PR alle Verwendungen dieses Konzepts mit der angegebenen Großschreibung abdeckt.