[docs] I need to use "cargo install tauri-cli" without network access

I am trying to build my pure rust based tauri based app (see https://codeberg.org/MaerchenfeeimGarten/doors_app/ ) for flathub. I need to install tauri-cli without using network access, but I cannot find any documentation for this featuring a clear step by step guide. Neither in the tauri documentation nor in the documentation from cargo. It is necessary because I have to use cargo tauri build inside the offline build environment for flatpak. It has to be architecture independend. All files necessary for this has to be downloaded using the syntax of the yaml file for building. So I cannot download using cargo something somthing as this will not work during build. I could download from crates.io if I would have the necessary url - but crates.io did not even freaturing a download link or raw file list - just the text saying I should use cargo install which is not possible without networking.

Start by reviewing the Tauri documentation and Cargo documentation for offline installation, then examine the Flatpak build context described in the issue. Document an architecture-independent, step-by-step process for obtaining the required files through the build YAML and running cargo tauri build without network access.