Fix typo in plugins deprecation message

Closes GH-719.

Author: marc2332

lib/react-markdown.js

@@ -41,7 +41,7 @@ const changelog =
 
 /** @type {Record<string, Deprecation>} */
 const deprecated = {
-  plugins: {to: 'plugins', id: 'change-plugins-to-remarkplugins'},
+  plugins: {to: 'remarkPlugins', id: 'change-plugins-to-remarkplugins'},
   renderers: {to: 'components', id: 'change-renderers-to-components'},
   astPlugins: {id: 'remove-buggy-html-in-markdown-parser'},
   allowDangerousHtml: {id: 'remove-buggy-html-in-markdown-parser'},