Finiding hugo, python, asciidoctor, asciidoctor-pdf, rougify in different platform so users do not need to create symbolic links manually

[minsoochoo0122_proton.me]

Summary

In adding cross-build description patch, I added the method to build doc on other platforms. However, some programs installed in /usr/bin/ may need to be added to /usr/local/bin/ because some package managers such as dnf and apt instsall in /usr/bin/. If this patch makes Makefile complicated, there is another solution to specify only the command. (for example, PYTHON_CMD=python3 instead of PYTHON_CMD=/usr/bin/local/python3)

Test Plan

Works fine on macOS and FreeBSD. It does not may on Linux, but it is the problem of distro. (see https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=255804)

[ygy]

I object to the platform-dependent changes to the Makefiles. It sounds unnecessary and error-prone to me. For example, different flavors of GNU/Linux could have different executable locations, and we can't and shouldn't attempt to support all of them.

[minsoochoo0122_proton.me]

In D31919#721867, @ygy wrote:

I object to the platform-dependent changes to the Makefiles. It sounds unnecessary and error-prone to me. For example, different flavors of GNU/Linux could have different executable locations, and we can't and shouldn't attempt to support all of them.

I understand that it would cause some errors. But I have a question: Why do we have to specify the location of programs?

[ygy]

In D31919#747119, @fel1x.mintchoco.development_gmail.com wrote:

In D31919#721867, @ygy wrote:

I object to the platform-dependent changes to the Makefiles. It sounds unnecessary and error-prone to me. For example, different flavors of GNU/Linux could have different executable locations, and we can't and shouldn't attempt to support all of them.

I understand that it would cause some errors. But I have a question: Why do we have to specify the location of programs?

I don't think this question is relevant to this revision which is trying to support multiple platforms officially. Worst case, we just override the commands when running make.

[debdrup]

The proper way to solve this would be to use /usr/bin/env $BINARY because if that doesn't work, the OS that the tree is being built on isn't POSIX-compliant at all.

However, there's an issue that as I see it is unsolvable, which is that as it is the Makefiles contains features that are exclusively found in BSD make - so it's not really possible to make it portable just by waving the right hashbang path at it.

[minsoochoo0122_proton.me]

I considered your ideas, and concluded that cross-platform build will cause confusion because of the differences between BSD make and GNU make. I'm closing this revision.