update quickstart
Add documentation link
removed PSPDFEnableOpenSSLFeatures check (it should be on the framework level);
Merge pull request #60 from PSPDFKit/denys/digital-signing-process

[READY] removed PSPDFEnableOpenSSLFeatures check (it should be on the framework level);
Remove unnecessary code
Update example
Merge branch 'master' into petr/issue-1792