build: add link to msune/autotools-skeleton

Add link to msune/autotools-skeleton project, a template to bootstrap
new projects with autotools (automake, autoconf, libtool...)

README.md

@@ -93,6 +93,8 @@ Tools that automate the building and testing of projects in C.
 
 * [Autotools][583] - Also known as the GNU build system (automake, autoconf, libtool...)
   is one of the most widely used build systems (configure && make). [GPL-1.0-or-later][335]
+* [Autotools project skeleton][584] - A simple autotools skeleton (template) to quickly bootstrap
+  new projects. [``BSD-2-Clause``][BSD-2-Clause]
 * [CMake][329] - Cross-platform family of tools designed to build, package and test
   software. [``BSD-3-Clause``][BSD-3-Clause]
 * [GNU Make][324] - Tool which controls the generation of executables and other
@@ -1732,3 +1734,4 @@ support for C.
 [581]: https://github.com/zeromq/libzmq
 [582]: https://www.infradead.org/~tgr/libnl/
 [583]: https://www.gnu.org/software/automake/manual/html_node/GNU-Build-System.html
+[584]: https://github.com/msune/autotools-skeleton