@signpdf/* 3.0.0

• Deprecating node-signpdf to be replaced by the @signpdf scoped packages;
• Split the helpers into separate packages @signpdf/placeholder-pdfkit010 and @signpdf/placeholder-plain;
• Decoupled the signing algorythm and the PDF signing process. Now @signpdf/signpdf understands PDFs and @signpdf/signer-p12 understands P12 and node-forge;
• sign() is now async to allow for hooking different signers;
• placeholder helpers now require contactInfo, location and name which used to be optional;
• Introduced examples in packages/examples;
• Introduced more types declarations through TS and JSDoc;