Added the word 'own' to the README file for design consistency

[Bchan1999]

Summary

After comparing the README file Component-Based description with the description on the React website, I noticed the README file was missing the word "own". For design consistency I added the word.

Reference: https://reactjs.org/

How did you test this change?

Since there was no change to the code and only the README file was modified, I ran no tests.

[sizebot]

Comparing: f0efa11...dbe2a30

Critical size changes

Includes critical production bundles, as well as any change greater than 2%:

Name	+/-	Base	Current	+/- gzip	Base gzip	Current gzip
oss-stable/react-dom/cjs/react-dom.production.min.js	=	134.97 kB	134.97 kB	=	43.23 kB	43.23 kB
oss-experimental/react-dom/cjs/react-dom.production.min.js	=	141.64 kB	141.64 kB	=	45.20 kB	45.20 kB
facebook-www/ReactDOM-prod.classic.js	=	486.06 kB	486.06 kB	=	86.51 kB	86.51 kB
facebook-www/ReactDOM-prod.modern.js	=	471.34 kB	471.34 kB	=	84.29 kB	84.29 kB
facebook-www/ReactDOMForked-prod.classic.js	=	486.06 kB	486.06 kB	=	86.51 kB	86.51 kB

Significant size changes

Includes any change greater than 0.2%:

(No significant changes)

Generated by 🚫 dangerJS against dbe2a30

[rbalicki2]

Looks good! Thanks for finding and fixing this.