Provide instructions using ycmd

[apupier]

see ycm-core/ycmd#1251 (comment)

it should be simplest way to achieve it currently

[apupier]

ycmd has been improved, see ycm-core/ycmd#1251 (comment)

so it should be "just" a matter of installing latest ycmd for emacs https://github.com/abingham/emacs-ycmd and configuring with something like:

let g:ycm_language_server = [{
    \ 'name': 'apache-camel',
    \ 'filetypes': [ 'java', 'xml' ],
    \ 'cmdline': java -jar PATH/TO/camel-language-server.jar
\}]