api-docs: fix typos in README and default path

Signed-off-by: MT Lewis <mtlewis@users.noreply.github.com>

.changeset/smart-plants-sip.md

@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-api-docs': patch
+---
+
+Fix typo in default path of api docs definition route

plugins/api-docs/README-alpha.md

@@ -826,10 +826,10 @@ export default createFrontendModule({
     createEntityContentExtension({
       // Name is necessary so the system knows that this extension will override the default 'definition' entity content extension provided by the 'api-docs' plugin
       name: 'definition',
-      // Returing a custom content component
+      // Returning a custom content component
       loader: () =>
         import('./components').then(m => (
-          <m.MyCustomApiDefintionEntityContent />
+          <m.MyCustomApiDefinitionEntityContent />
         )),
     }),
   ],

plugins/api-docs/src/alpha.tsx

@@ -189,7 +189,7 @@ const apiDocsProvidingComponentsEntityCard = EntityCardBlueprint.make({
 const apiDocsDefinitionEntityContent = EntityContentBlueprint.make({
   name: 'definition',
   params: {
-    defaultPath: '/defintion',
+    defaultPath: '/definition',
     defaultTitle: 'Definition',
     filter: 'kind:api',
     loader: async () =>