public/ README

The header files in this directory are the only ones that should ever be
included by an embedder of PDFium.  If there arises a need for functionality
beyond what is present here, then a new API must be added here to provide it.

These header files must be entirely contained in this directory; they must
never include other header files from outside of it.

These files must compile cleanly without warnings on both C and C++ compilers.

Changes to these files must be carefully considered to avoid breaking
compatibility.
