when I use static link method to compile , result is undefined with pthread_create, so we should add -lpthread

* Fix typo
* Improve platforms sentence

* Update backers link to OpenBLAS repo
* Remove reference to Bountysource

* Fold "Users of OpenBLAS", "Publications", "Mailing list", "Donation" pages into "About"
* Remove full license
* Remove outdated TODO and machine list pages
* Shorter titles for CI and distributing pages
* Link to GotoBLAS readme in repo
* Brief description of OpenBLAS in homepage
* Move acknowledgements into About page
* Remove manual TOC in FAQ docs

* Fix more broken links
* Move FAQ last
* Fold all install-y content into `install.md`
* Fix header levels
* Fold `download.md` contents into `install.md`
* Fix cross-references
* Ordered navigation
* Add logo to docs
* Make doc pages more consistent

This touches on the following:

- build configurations
- naming of symbols, shared/static libraries and other build outputs
  like pkg-config and CMake files
- (in more detail) guidance on ILP64 builds

It tries to explain that, while this is only guidance and there may be
reasons to deviate from that, for some build options there are best
practices, and for some others there are choices to make.

It also links to a number of well-maintained build recipes in order
to help packagers of other distros make choices.

Closes gh-3798

[skip ci]