docs(readme): mention peer dependencies

Author: openscript

README.md

@@ -11,6 +11,13 @@ Add the package with the package manager via NPMs registry of choice to your pro
 - **pnpm**: `pnpm add react-section-dividers`
 - **npx**: `npx -p react-section-dividers`
 
+Besides `react` and `react-dom` this package has `@emotion/react` as a peer dependency. Make sure it is a dependency of your project:
+
+- **yarn**: `yarn add @emotion/react`
+- **npm**: `npm install @emotion/react`
+- **pnpm**: `pnpm add @emotion/react`
+- **npx**: `npx -p @emotion/react`
+
 ## Dividers
 
 ### Aslant