[MINOR][DOC] ADD toc for monitoring page

### What changes were proposed in this pull request?

Add toc tag on monitoring.md

### Why are the changes needed?

fix doc

### Does this PR introduce _any_ user-facing change?

yes, the table of content of the monitoring page will be shown on the official doc site.

### How was this patch tested?

pass GA doc build

Closes #32545 from yaooqinn/minor.

Authored-by: Kent Yao <yao@apache.org>
Signed-off-by: Kent Yao <yao@apache.org>
This commit is contained in:
Kent Yao 2021-05-14 14:19:15 +08:00
parent 9ea55fe771
commit d424771ec2

View file

@ -19,6 +19,9 @@ license: |
limitations under the License.
---
* This will become a table of contents (this text will be scraped).
{:toc}
There are several ways to monitor Spark applications: web UIs, metrics, and external instrumentation.
# Web Interfaces