[APM] Docs: Show note that specifically IE11 support is limited for service maps

[formgeist]

Summary

We're currently encountering a larger issue where the service map does not load in IE11, possibly due to the framework we're using. While we're investigating, I would like to use this as an opportunity to show a note for users in our documentation (since we can't display a message in the UI) that support for IE11 is limited due because it's a legacy browser and that we recommend using i.e. Chrome or Firefox is available. The feature itself is in beta, so users will be aware that things might not work as expected, but this still feels big enough that we want to specifically call it out.

@bmorelli25 Sorry for the short notice, but will you be able to put this in the Service maps documentation for 7.7?

For reference, related issue for the IE11 bug: #63113

[elasticmachine]

Pinging @elastic/apm-ui (Team:apm)

[bmorelli25]

Not a problem!