docs: address issue #24218 (#24220)

## Summary
Fixed malformed anchor link by removing `.md` extension from the anchor
portion.

## Changes
- Fixed anchor link in
`content/manuals/desktop/features/networking/networking-how-tos.md` from
`#firewalls-and-endpoint-visibility.md` to
`#firewalls-and-endpoint-visibility`

Fixes #24218

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Co-authored-by: aevesdocker <102604716+aevesdocker@users.noreply.github.com>

Author: github-actions[bot]

content/manuals/desktop/features/networking/networking-how-tos.md

@@ -86,7 +86,7 @@ Docker Desktop networking can work when attached to a VPN.
 To do this, Docker Desktop intercepts traffic from the containers and injects it into
 the host as if it originated from the Docker application.
 
-For details about how this traffic appears to host firewalls and endpoint detection systems, see [Firewalls and endpoint visibility](/manuals/desktop/features/networking/index.md#firewalls-and-endpoint-visibility.md).
+For details about how this traffic appears to host firewalls and endpoint detection systems, see [Firewalls and endpoint visibility](/manuals/desktop/features/networking/index.md#firewalls-and-endpoint-visibility).
 
 ### Working with proxies