Update translations: downloads, libraries, ruby-core, manual-instructions

[stomar]

There have been major changes of these pages in the last years, and essentially all translations are outdated:

• downloads
• libraries
• community/ruby-core
• community (small change: paragraph regarding ruby-core)
• community/mailing-lists/manual-instructions (small changes)

(Some recent changes are these: 59584c5, 6587577, 98ecf2e, but there have been major changes before the migration to GitHub.)

[chikamichi]

Major project ahead… I will be starting by ensuring /fr is in sync, right now.

[chikamichi]

@stomar I updated 🇫🇷 (8589786). While editing, I noticed a few area for improvement.

Installation

Pretty up-to-date, but could benefit from mentioning alternatives to RVM.

Maybe a more "standardized" layout to maintain consistency among the different platform could help. For instance:

Mac OS X

• Preferred way: Homebrew
• Best alternative: a third-party tool (RVM…)

Blablabla about installing on Mac OS X, different versions…

Windows

• Preferred way: RubyInstaller
• Best alternative: RailsInstaller for Rails, or a third-party tool (RVM…)

Blablabla about installing on Windows, different versions…

Also, there are no instructions about compiling from source, svn commands to fetch the code and stuff.

Libraries

What about a complete, real-world example? It would describe a typical use-case, from looking for a library by theme to installing and using it in one's code.

Both Ruby-Doc.org and RubyDoc.info should be mentionned.

Ruby Toolbox could definitely be promoted as a way to explore Ruby's ecosystem.

[fuadsaud]

Hmm, I'l try to update pt soon.

@chikamichi nice ideas; the installation workflow could be more detailed and reflect the current installation methods (rvm, ruby-build, etc) and explain the use cases and basic workflow for managing multiple versions (mentioning tools like rbenv and chruby).

[postmodern]

@chikamichi should we make a separate issue for compiling from source. I donate the instructions from the chruby wiki.

[stomar]

Some information on getting the source code via SVN is on the ruby-core page.

[stomar]

I only made the most necessary changes to get the content up-to-date.
For discussions on bigger reworkings I think there should be separate issues.

[stomar]

Also updated: community/ruby-core and the link to it on the community page.