Remove unnecessary linefeeds from markdown files

Hello docrails team,
I'm now translating docrails guides into Japanese and I'd like to send a pull request to remove unnecessary linefeeds, which disturbs our localization process. 
To use localization tools such as Google Translator Toolkit or TRADOS, the source sentence should be "well-formed", which means no extra linefeeds are contained. See http://en.wikipedia.org/wiki/Translation_memory.
Please note that I haven't changed any sentences except removing linefeeds.
I guess other countries' translators would request the fixes as well.
I hope you understand and accept the request. 
Best regards,