Please add pkg-config .pc file

Something like this:

```
Name: zfp
Description: Library for compressed numerical arrays that support high throughput read and write random access
Requires:
Version: 0.5.3
Libs: -L/usr/local/lib -lzfp
Cflags: -I/usr/local/include
```

Use the issue's sample metadata as the target and inspect the repository's build and installation configuration to determine where package metadata belongs. Done means the project provides a pkg-config file describing zfp with the requested name, version, library, include path, and description.

Written by the indexing model from the issue text.