index.patch

$ diff -u node_modules/gatsby-theme-docz/src/index.js src/gatsby-theme-docz/index.js 
--- node_modules/gatsby-theme-docz/src/index.js	2019-09-04 11:26:27.155000000 -0400
+++ src/gatsby-theme-docz/index.js	2019-09-05 09:15:05.869936223 -0400
@@ -5,12 +5,17 @@
 
 import defaultTheme from '~theme'
 import components from '~components'
+import Notice from '../components/Notice'
 
 const Theme = ({ children }) => {
   const config = useConfig()
+  const allComponents = {
+      ...components,
+      Notice
+  }
   return (
     <ThemeProvider theme={config.themeConfig}>
-      <ComponentsProvider components={components}>
+      <ComponentsProvider components={allComponents}>
         <Styled.root>{children}</Styled.root>
       </ComponentsProvider>
     </ThemeProvider>