Add steps to how setup Butterfly with Nextcloud in storage.md #6419

Job	Run time
build-macos	5m 8s
build-snap (ubuntu-24.04, x86_64, x64, x86_64)	7m 18s
build-msix	7m 47s
build-linux (ubuntu-24.04, x86_64, x64, x86_64)	3m 19s
build-ipa (iOS)	5m 49s
build-linux (ubuntu-24.04-arm, arm64, arm64, aarch64)	4m 4s
build-snap (ubuntu-24.04-arm, arm64, arm64, aarch64)	8m 1s
build-linux (ubuntu-22.04, alternative-x86_64, x64, x86_64)	3m 26s
build-linux (ubuntu-22.04-arm, alternative-arm64, arm64, aarch64)	3m 36s
build-windows	8m 45s
build-apk	15m 11s
deploy-to-play-store	0s
build-docker	0s
deploy	0s
publish-winget	0s
	1h 12m 24s

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