style(birdnet-pi-zach): blank lines around the new CHANGELOG entry

Codacy flagged 3 new issues on this PR while the byte-identical 99-run.sh change
passed on #2972, which narrowed it to the CHANGELOG entry I wrote by hand.

The entry had no blank line after its heading and none before the heading below
it — MD022 (headings surrounded by blank lines) and MD032 (lists surrounded by
blank lines). Neither is disabled in .markdownlint.yaml; only MD001, MD002,
MD012, MD013, MD025, MD033 and MD041 are. The birdnet-pi entry for the same fix
has the blank line, which is why it passed.

The rest of this file has the same missing blank lines throughout, but those are
pre-existing lines that Codacy does not count and this change does not touch.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

birdnet-pi-zach/CHANGELOG.md

@@ -1,6 +1,8 @@
 ## 2026.08.15 (15-08-2026)
+
 - Fix: `ALSA_CARD` now really selects the microphone. Its value was copied as-is into `REC_CARD`, but BirdNET-Pi hands `REC_CARD` to `arecord -D` / `ffmpeg -f alsa -i`, which expect an ALSA PCM name: a card index such as `1` gave `Unknown PCM 1` and no recording at all. It is now converted to `plughw:CARD=<value>,DEV=0`, while a value that already is a PCM name (`dsnoop:CARD=Audio,DEV=0`, `default`, `null`, `pulse`, `pipewire`, ...) is used as provided
 - Fix: writing `REC_CARD` no longer detaches `birdnet.conf` from `/config`. `sed -i` replaced the `$HOME/BirdNET-Pi/birdnet.conf` symlink with a regular file, so later edits from the WebUI went to a different file than the one the add-on had written; it now edits `/config/birdnet.conf` with `--follow-symlinks`
+
 ## 2026.07.10-2 (10-07-2026)
 - Minor bugs fixed
 ## 2026.07.10 (10-07-2026)