Support MinGW build and added CI

[ptrrsn]

Adding instructions to build m4rie on MinGW on Windows and CI. On MSYS2, the Linux symlink from m4rie to src is not properly recognized. Therefore, we need to create the symlink manually before running autoreconf. A cleaner solution will be to add a shell script to run the ln and autoreconf commands instead of just running autoreconf, but that will force people to change their workflow. Hence, I choose this one instead. What do you think? @malb

As a context: sagemath/sage#38872

cc: @dimpase @tobiasdiez

[ptrrsn]

(the README.md text for Windows support is from m4ri)

[dimpase]

it's quite common to have a script called bootstrap or autogen to run the needed autotools and related commands.

[ptrrsn]

Yes, having an autogen will be ideal. @malb can I add an autogen to support Windows that will replace the direct autoreconf --install call?

[dimpase]

looks OK, that typo should be fixed. I haven't tried these on a Windows machine though

[malb]

Yes, having an autogen will be ideal. @malb can I add an autogen to support Windows that will replace the direct autoreconf --install call?

That'd be fab.

[ptrrsn]

Thank you for the reviews, I added autogen.sh and updated the documentations and workflows.

[dimpase]

while you at it, can we also get C++17 compliance, by removing register everywhere?

[dimpase]

while you at it, can we also get C++17 compliance, by removing register everywhere?

this is now #5

[ptrrsn]

Ah, sorry for the late response. Thank you for the PR.