Docs housekeeping post-6.2.0 (#394)

* remove leftover css

Signed-off-by: Peter Jun Park <peter.park@amd.com>

* fix link to panel_config_template.yaml

Signed-off-by: Peter Jun Park <peter.park@amd.com>

* add note in archived docs pointing to latest

Signed-off-by: Peter Jun Park <peter.park@amd.com>

rm repetition

---------

Signed-off-by: Peter Jun Park <peter.park@amd.com>

docs/archive/docs-2.x/index.md

@@ -1,5 +1,10 @@
 # Welcome to the [Omniperf](https://github.com/ROCm/omniperf) Documentation!
 
+```{warning}
+This version of the documentation is archived and contains out-of-date information.
+See [Omniperf documentation](https://rocm.docs.amd.com/projects/omniperf/en/latest/index.html) for the latest version.
+```
+
 ```eval_rst
 .. toctree::
    :glob: