Modify docs to get more algorithms in the ToC

[tonyelewis]

Here's a PR for #55.

I found it tricky to manipulate the sections to get the entries I wanted in the ToC, such that their links help navigation. I've managed to get something sensible working here. However I should highlight that these changes have:

• put the sections of text inline within one page per parent category (such as "C++11 Algorithms")
• nested each of the groups of algorithms within another untitled section (because otherwise, I couldn't get them all to appear on the same page)

And of course those changes may have broken some previous URLs into the docs.

What do you think? I think this is broadly a change in the right direction but I'd welcome any suggestions you have about better ways to achieve the same goals.

[tonyelewis]

I failed to notice that this PRs build had failed but I think that was actually nothing to do with the PR's changes to the docs. I've just pushed a trivial change to see if that triggers a clean build.

[tonyelewis]

Now all the builds have failed :grimacing: …

$ ./b2 headers
boost-install.jam: No such file or directory
Jamroot:307: in boost-install
ERROR: rule "boost-install.boost-install" unknown in module "Jamfile</home/travis/build/boostorg/boost-root>".
libs/chrono/build/Jamfile.v2:113: in modules.load
/home/travis/build/boostorg/boost-root/tools/build/src/build/project.jam:372: in load-jamfile
/home/travis/build/boostorg/boost-root/tools/build/src/build/project.jam:64: in load
/home/travis/build/boostorg/boost-root/tools/build/src/build/project.jam:89: in load-used-projects
/home/travis/build/boostorg/boost-root/tools/build/src/build/project.jam:75: in load
/home/travis/build/boostorg/boost-root/tools/build/src/build/project.jam:142: in project.find
/home/travis/build/boostorg/boost-root/tools/build/src/build-system.jam:618: in load
/home/travis/build/boostorg/boost-root/tools/build/src/kernel/modules.jam:295: in import
/home/travis/build/boostorg/boost-root/tools/build/src/kernel/bootstrap.jam:139: in boost-build
/home/travis/build/boostorg/boost-root/boost-build.jam:17: in module scope
The command "./b2 headers" failed and exited with 1 during .
Your build has been stopped.

But I don't think this anything to do with the changes in my PR.

[mclow]

Manually applied on develop as a814721

[tonyelewis]

Thanks for this. Shall I close this PR then?

(As it happens, I've just been watching your std::midpoint() CppCon talk on the tube this morning. I'm currently up to the {oops - literal 0 is also a null pointer} point. It's a great talk - thanks.)

[mclow]

I will close it when I merge to master - probably later today.

[mclow]

merged to master for the 1.72.0 release.