Do not require double-nesting of custom TechDocs readers.

Signed-off-by: Eric Peterson <ericpeterson@spotify.com>

docs/features/techdocs/how-to-guides.md

@@ -162,11 +162,11 @@ The `techDocsPage` is a default techdocs reader page which lives in
 having to set anything up.
 
 ```tsx
-<TechDocsReaderPage>
+<Page themeId="documentation">
   <TechDocsReaderPageHeader />
   <TechDocsReaderPageSubheader />
   <TechDocsReaderPageContent />
-</TechDocsReaderPage>
+</Page>
 ```
 
 If you would like to compose your own `techDocsPage`, you can do so by replacing
@@ -174,30 +174,30 @@ the children of TechDocsPage with something else. Maybe you are _just_
 interested in replacing the Header:
 
 ```tsx
-<TechDocsReaderPage>
+<Page themeId="documentation">
   <Header type="documentation" title="Custom Header" />
   <TechDocsReaderPageContent />
-</TechDocsReaderPage>
+</Page>
 ```
 
 Or maybe you want to disable the in-context search
 
 ```tsx
-<TechDocsReaderPage>
+<Page themeId="documentation">
   <Header type="documentation" title="Custom Header" />
   <TechDocsReaderPageContent withSearch={false} />
-</TechDocsReaderPage>
+</Page>
 ```
 
 Or maybe you want to replace the entire TechDocs Page.
 
 ```tsx
-<TechDocsReaderPage>
+<Page themeId="documentation">
   <Header type="documentation" title="Custom Header" />
   <Content data-testid="techdocs-content">
     <p>my own content</p>
   </Content>
-</TechDocsReaderPage>
+</Page>
 ```
 
 ## How to migrate from TechDocs Alpha to Beta