Unable to install if no binary available #99
Description
Problem
Unable to use themekit on arm64 linux (or any other system where there is no binary available)
Replication steps
Run "npm install -g @shopify/themekit" on arm64 linux.
More Information
It seems like themekit doesn't allow any sort of fallback to build if there is no binary available for the architecture. Most other NPM packages use this approach, so that those on different architectures can still use the software (at the cost of compile time). Alternatively, themekit should at least allow the user to use a system installation of themekit if available, which would help alleviate the issue.
I tried building themekit manually (which worked quite well on arm64) and then symlinking the binary to the bin in the node-themekit directory. However, node-themekit seems to force the installation by deleting the binary & then trying to re-install (which fails since there is no arm64 linux binary).
I think having some sort of fallback would be good, even if the arm64 binary does get added eventually. This way we could also install themekit on something like RISC or other alternative architectures.
Having this fallback could also help getting the build working for ARM-based macbooks.