Exclude test data and tools from published packages

During our dependency reviews we discovered that the ttf-parser crate as
uploaded to crates.io includes test data and additional tools that are
not used by the rust code. This increases the package size and makes it
harder to review the source code.

This commit explicitly includes only relevant files. This helps to
reduce the package size

Before: 118 files, 1.0MiB (198.4KiB compressed)
After: 75 files, 747.1KiB (140.6KiB compressed)

Overall based on the reduction in the compressed package size and the
current download numbers that results to a traffic reduction for
crates.io of around 110GB / Month.

Author: weiznich

Cargo.toml

@@ -16,7 +16,7 @@ documentation = "https://docs.rs/ttf-parser/"
 readme = "README.md"
 edition = "2018"
 rust-version = "1.63.0"
-exclude = ["benches/**"]
+exclude = ["benches/", "tests/", "testing-tools/", "examples/", "meson.build"]
 
 [dependencies]
 core_maths = { version = "0.1.0", optional = true } # only for no_std builds