Broken URL for resources

[sindhujag95]

The following links are broken / not working:

S.No	Section	Link	URL
1	Prerequisites	React Components, Elements, and Instances	https://facebook.github.io/react/blog/2015/12/18/react-components-elements-and-instances.html
2	Prerequisites, What is reconciliation?	Reconciliation	https://facebook.github.io/react/docs/reconciliation.html
3	Prerequisites, Scheduling	React Design Principles	https://facebook.github.io/react/contributing/design-principles.html
4	Structure of a fiber -> pendingWorkPriority	ReactPriorityLevel	https://github.com/facebook/react/blob/master/src/renderers/shared/fiber/ReactPriorityLevel.js

[tanshunyuan]

Found the URLs for the broken links

Broken Links	Updated Links
React Components, Elements, and Instances	https://legacy.reactjs.org/blog/2015/12/18/react-components-elements-and-instances.html
Reconciliation	https://react-legacy.netlify.app/docs/reconciliation.html
React Design Principles	https://react-legacy.netlify.app/contributing/design-principles.html
ReactPriorityLevel	https://github.com/facebook/react/blob/1c1f68e8dccbc84acfae66178493dbfb8ca7d1e1/src/renderers/shared/fiber/ReactPriorityLevel.js