Refactor layout (#486)

* Refactor to move `<DatasetContainer>` out of layout
* `<DatasetContainer>` is now in the methodology page. Starting the review there will help understand the motive for this change.
* Fixed 404 page which seems way out of date.
* Use row/col grid syntax

client/src/components/J40MainGridContainer.tsx

@@ -0,0 +1,30 @@
+// Trussworks GridContainer won't allow it to span 100% of the page, so
+// this works around it and tries to hide the complexity in component
+import React, {ReactNode} from 'react';
+import {GridContainer} from '@trussworks/react-uswds';
+
+interface ILayoutProps {
+  children: ReactNode,
+  fullWidth?: boolean,
+  className?: string
+}
+
+const J40MainGridContainer = ({
+  children,
+  fullWidth = false,
+  className = 'j40-grid-container'}: ILayoutProps) => {
+  return fullWidth ? (
+    <div
+      className={'j40-grid-container ' + className}>
+      {children}
+    </div>
+  ) : (
+    <GridContainer
+      containerSize={'desktop-lg'}
+      className={'j40-grid-container ' + className}>
+      {children}
+    </GridContainer>
+  );
+};
+
+export default J40MainGridContainer;

client/src/components/layout.tsx

@@ -1,10 +1,7 @@
 import React, {ReactNode} from 'react';
-import {GridContainer, Grid} from '@trussworks/react-uswds';
 import J40Header from './J40Header';
 import J40Footer from './J40Footer';
 import {URLFlagProvider} from '../contexts/FlagContext';
-import DatasetContainer from '../components/DatasetContainer';
-// this has to be wrong
 
 interface ILayoutProps {
   children: ReactNode,
@@ -12,22 +9,13 @@ interface ILayoutProps {
 }
 
 const Layout = ({children, location}: ILayoutProps) => {
-  const isMethodologyPage = location.pathname.match(/methodology\/?/);
-
   // @ts-ignore
   return (
     <URLFlagProvider location={location}>
       <J40Header location={location}/>
-      <GridContainer containerSize={'desktop-lg'}
-        className={'j40-grid-container'}>
-        <Grid row>
-          <main id={'main-content'}
-            className={'usa-layout-docs j40-main-content desktop:grid-col-12'}>
-            {children}
-          </main>
-        </Grid>
-      </GridContainer>
-      {isMethodologyPage ? <DatasetContainer />: null}
+      <main id={'main-content'}>
+        {children}
+      </main>
       <J40Footer/>
     </URLFlagProvider>
   );