Add PCRE2 related URLs to global.ent

In preparation for revisions to the PCRE Extension reference chapter. The older URLs are mostly for the PCRE1 library which isn't applicable since PHP 7.3.0.

Author: joshtrichards

entities/global.ent

@@ -387,6 +387,11 @@
 <!ENTITY url.pcre.changelog "http://www.pcre.org/original/changelog.txt">
 <!ENTITY url.pcre.man "http://www.pcre.org/pcre.txt">
 <!ENTITY url.pcre2.changelog "https://github.com/PCRE2Project/pcre2/blob/master/NEWS">
+<!ENTITY url.pcre2.github "https://github.com/PCRE2Project/pcre2">
+<!ENTITY url.pcre2.limits "https://pcre2project.github.io/pcre2/doc/pcre2limits/">
+<!ENTITY url.pcre2.man "https://pcre2project.github.io/pcre2/doc/">
+<!ENTITY url.pcre2.perlcompat "https://pcre2project.github.io/pcre2/doc/pcre2compat/">
+<!ENTITY url.pcre2.website "https://pcre2project.github.io/pcre2/">
 <!ENTITY url.pdf "http://www.pdflib.com/products/pdflib-family/">
 <!ENTITY url.pdf.fpdf "http://www.fpdf.org/">
 <!ENTITY url.pdf.tcpdf "http://www.tcpdf.org/">