doc: Improve cmake instructions in README

[fjahr]

Minor improvement suggestion for the readme. I find this alternative way of using cmake a bit more comfortable because I don't like to change the directory.

It's just a suggestion based on personal preference, if this is too minor of an improvement feel free to close.

[real-or-random]

I happen to find this a tiny bit more comfortable, too, but IIRC we had discussed this (I can't find the discussion) and @hebasto argued that the tutorial cds into the build directory. I also think that mkdir build && cd build is a bit more self-documentary to people not familiar with CMake because it makes clear that build is a directory and not some CMake command or something.

No strong opinion from my side, but I think there are good reasons for what we have currently.

[fjahr]

@real-or-random alright, thanks for the info, closing it for now

[hebasto]

FWIW, while working on the CMake staging branch for Bitcoin Core, the rough consensus has been reached not to suggest using cd in the build docs (see https://github.com/bitcoin/bitcoin/blob/master/doc/build-*.md).

[fjahr]

Ok, reopening since @real-or-random seemed in favor and I take from @hebasto 's comment that the argument for cd-ing seems not so relevant anymore and this would align the instructions here with bitcoin core.

[fjahr]

Fixed comments from @hebasto, thanks!

[real-or-random]

utACK 93363fa

[hebasto]

To unify all examples, -S . can be dropped from the example for Windows.

[fjahr]

Thanks, took the suggested changes and removed the -S . from the windows example too.

[real-or-random]

LGTM but sorry, a last nit: Perhaps then the comments for the autotools build should also be improved for consistency.

    $ ./autogen.sh       # Generate a ./configure script
    $ ./configure        # Generate a build system
    $ make               # Run the actual build process
    $ make check         # Run the test suite
    $ sudo make install  # Install the library into the system (optional)

And indenting to the same column is more readable, and then should also be done for the CMake instructions for consistency.

[fjahr]

@real-or-random no worries, applied all the suggested changes

[hebasto]

ACK 2ac9f55.

[real-or-random]

utACK 2ac9f55