Improve build docs and optimize Dockerfile for Android and Linux builds (#2016)

* Update build docs and migrate Android builds to Docker

* Update NDK and move steps directly into Dockerfile

* Fix NDK installation via script and Dockerfile

* Migrate to @MrCyjaneK's existing Dockerfile (with optimizations)

* Add .dockerignore and migrate Dockerfile to root of project

* Revert .gitignore changes

* Update Android and Linux builds and resolve Linux build issue

* Fix git repo for Linux and Android build instructions

* Set branch to latest release in build docs

* Ensure `flutter clean` is run before building

* Fix Linux completion example

* Don't build Zano for Linux

* Apply suggestions from code review

Co-authored-by: cyan <cyjan@mrcyjanek.net>

* Explicitly add automake package to Dockerfile

* Improve logging on Android and Linux builds via Docker

* Improve Dockerfile comments and ordering

* Fix issues in macOS and iOS builds docs (thanks @MrCyjaneK)

* Update docs/builds/IOS.md [skip ci]

* Update docs/builds/IOS.md [skip ci]

* Update docs/builds/MACOS.md [skip ci]

* Update docs/builds/IOS.md [skip ci]

* Fix and improve iOS and macOS build docs

* Windows build doc improvements

Co-authored-by: cyan <cyjan@mrcyjanek.net>

* add missing dependency to Dockerfile

* Update Windows build docs

* More fixes and optimizations to the Windows build docs

* Add git config to Windows build doc

* Fix shell location/commands in Windows build doc

* Fix WSL commands in Windows build doc

* Apply suggestions from code review

Co-authored-by: cyan <cyjan@mrcyjanek.net>

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Co-authored-by: cyan <cyjan@mrcyjanek.net>

.dockerignore

@@ -0,0 +1 @@
+*