Add simple examples

[Bruno Haible]

When modifying complicated aspects of the gnulib-tool generated Makefiles,
I found it useful to have a couple of examples ready, to avoid regressions.
I am adding them here.

Paul, if you want, you are welcome to add a 'hello-c-gnumake' example,
that shows the --gnu-make option. I guess you are relying on this in Emacs,
therefore it should be part of regression testing.


2021-12-15  Bruno Haible  <bruno@clisp.org>

        Add simple examples.
        * examples: New directory.

examples/README
examples/hello-c-nognulib/INSTALL
examples/hello-c-nognulib/Makefile.am
examples/hello-c-nognulib/autoclean.sh
examples/hello-c-nognulib/autogen.sh
examples/hello-c-nognulib/configure.ac
examples/hello-c-nognulib/hello.c
examples/hello-c-nognulib/m4/Makefile.am
examples/hello-c-gnulib/INSTALL
examples/hello-c-gnulib/Makefile.am
examples/hello-c-gnulib/autoclean.sh
examples/hello-c-gnulib/autogen.sh
examples/hello-c-gnulib/configure.ac
examples/hello-c-gnulib/hello.c
examples/hello-c-gnulib/m4/Makefile.am
examples/hello-c-gnulib-automakesubdir/INSTALL
examples/hello-c-gnulib-automakesubdir/Makefile.am
examples/hello-c-gnulib-automakesubdir/autoclean.sh
examples/hello-c-gnulib-automakesubdir/autogen.sh
examples/hello-c-gnulib-automakesubdir/configure.ac
examples/hello-c-gnulib-automakesubdir/m4/Makefile.am
examples/hello-c-gnulib-automakesubdir/src/hello.c
examples/hello-c-gnulib-automakesubdir/src/local.mk
examples/hello-c-gnulib-automakesubdir-withtests/INSTALL
examples/hello-c-gnulib-automakesubdir-withtests/Makefile.am
examples/hello-c-gnulib-automakesubdir-withtests/autoclean.sh
examples/hello-c-gnulib-automakesubdir-withtests/autogen.sh
examples/hello-c-gnulib-automakesubdir-withtests/configure.ac
examples/hello-c-gnulib-automakesubdir-withtests/m4/Makefile.am
examples/hello-c-gnulib-automakesubdir-withtests/src/hello.c
examples/hello-c-gnulib-automakesubdir-withtests/src/local.mk
examples/hello-c-gnulib-nonrecursive/INSTALL
examples/hello-c-gnulib-nonrecursive/Makefile.am
examples/hello-c-gnulib-nonrecursive/autoclean.sh
examples/hello-c-gnulib-nonrecursive/autogen.sh
examples/hello-c-gnulib-nonrecursive/configure.ac
examples/hello-c-gnulib-nonrecursive/m4/Makefile.am
examples/hello-c-gnulib-nonrecursive/src/hello.c
examples/hello-c-gnulib-nonrecursive/src/local.mk