Add link to wiki/Authors and graph/authors to AUTHORS.md

Author: zonuexe

AUTHORS.md

@@ -114,3 +114,7 @@ Names Sorted Alphabetically:
 - tijsmallaerts
 - zapad
 - 顾伟刚
+
+A chronological list of pre-2019 contributors can be found at [wiki/Authors](https://github.com/emacs-php/php-mode/wiki/Authors).
+
+Contributors since 2011, where this project was hosted, can also be found at [graphs/contributors](https://github.com/emacs-php/php-mode/graphs/contributors), except for accounts that have been withdrawn from GitHub.

Makefile

@@ -18,6 +18,7 @@ AUTHORS.md: etc/git/AUTHORS.md.in .mailmap
 		&& (cat $< > $@ \
 			&& git log --pretty=format:'- %aN' | \
 			cat etc/git/former-contributors - | LANG=C sort -u >> $@ \
+			&& cat etc/git/AUTHORS2.md.in >> $@ \
 			&& printf "FINISHED\n" ; ) \
 		|| printf "FAILED (non-fatal)\n"
 

etc/git/AUTHORS2.md.in

@@ -0,0 +1,4 @@
+
+A chronological list of pre-2019 contributors can be found at [wiki/Authors](https://github.com/emacs-php/php-mode/wiki/Authors).
+
+Contributors since 2011, where this project was hosted, can also be found at [graphs/contributors](https://github.com/emacs-php/php-mode/graphs/contributors), except for accounts that have been withdrawn from GitHub.