Update docs with instructions on installing pdgraster on devices with Apple Silicon chips

[robyngit]

I ran into issues installing pdgraster on a Mac with an Apple Silicon chip (M2). Since other developers might hit similar roadblocks, we may want to eventually update the docs with some additional instructions. For now, I just wanted to document the steps I took to get it working in case I or others need to refer to it the future.

Pillow library

The Pillow library was not being installed with the correct architecture (ARM64) binaries.

Steps to resolve:

pip uninstall pillow
pip cache purge
export CFLAGS="-arch arm64"
export LDFLAGS="-arch arm64"
pip install --no-cache-dir --no-binary :all: "Pillow>=9,<10"

Because the error message initially mentioned jpeg I also initially installed it via brew, however, I don't know if this was necessary in the end.

arch -arm64 brew install jpeg

libspatialindex install

To install libspatialindex I had to use the brew command with the arch flag to specify the architecture:

arch -arm64 brew install spatialindex

pdgstaging install?

I installed pdgraster using pip install -e . I'm not sure why it failed to install pdgstaging (since it is listed in setup.py), but I had to install it manually using pip install git+https://github.com/PermafrostDiscoveryGateway/viz-staging. This might be unique to my particular case, but I wanted to document it here in case others run into the same issue.