Prepare package configurations for publishing.

[xStrom]

I went over all the Cargo.toml files to get them ready for the upcoming publishing.

• Enabled publish for vello itself.
• Bumped vello version to 0.1.0.
• Removed the workspace version. Every published crate gets its own dedicated version, which for now only means vello & vello_encoding.
• Added rust-version to document the reality of 1.75 being needed to compile vello at this moment.
• Excluded some needless files from being bundled when publishing, which is going to reduce the size of the published package by ~1MB !!
• Promoted some dependencies to workspace dependencies.
• Reordered some properties to get them into consistent order in all files.

[xorgy]

Looks good overall, but I would like that one added comment and clarification on the MSRV.

[DJMcNab]

Generally looks reasonable

[DJMcNab]

Thanks for this - these are useful improvements

[xorgy]

LGTM