docs: add back issue code links (#10903)

* docs: add back issue code links

closes: https://github.com/apache/incubator-superset/issues/10852

* Addressing comments

docs/src/pages/docs/Miscellaneous/issue_codes.mdx

@@ -0,0 +1,45 @@
+---
+name: Issue Codes
+menu: Miscellaneous
+route: /docs/miscellaneous/issue-codes
+index: 3
+version: 1
+---
+
+# Issue Code Reference
+
+This page lists issue codes that may be displayed in
+Superset and provides additional context.
+
+## Issue 1000
+
+```
+The datasource is too large to query.
+```
+
+It's likely your datasource has grown too large to run the current
+query, and is timing out. You can resolve this by reducing the
+size of your datasource or by modifying your query to only process a
+subset of your data.
+
+## Issue 1001
+
+```
+The database is under an unusual load.
+```
+
+Your query may have timed out because of unusually high load on the
+database engine. You can make your query simpler, or wait until the
+database is under less load and try again.
+
+## Issue 1002
+
+```
+The database returned an unexpected error.
+```
+
+Your query failed because of an error that occurred on the database.
+This may be due to a syntax error, a bug in your query, or some other
+internal failure within the database. This is usually not an
+issue within Superset, but instead a problem with the underlying
+database that serves your query.

superset-frontend/src/addSlice/AddSliceContainer.tsx

@@ -122,7 +122,7 @@ export default class AddSliceContainer extends React.PureComponent<
                   'If the datasource you are looking for is not available in the list, follow the instructions on how to add it in the Superset tutorial.',
                 )}{' '}
                 <a
-                  href="https://superset.apache.org/tutorial.html#adding-a-new-table"
+                  href="https://superset.apache.org/docs/creating-charts-dashboards/first-dashboard#adding-a-new-table"
                   rel="noopener noreferrer"
                   target="_blank"
                 >

superset-frontend/src/components/ErrorMessage/IssueCode.tsx

@@ -28,7 +28,7 @@ export default function IssueCode({ code, message }: IssueCodeProps) {
     <>
       {message}{' '}
       <a
-        href={`https://superset.apache.org/issue_code_reference.html#issue-${code}`}
+        href={`https://superset.apache.org/docs/miscellaneous/issue-codes#issue-${code}`}
         rel="noopener noreferrer"
         target="_blank"
       >