Add redirections

I think it will be good to redirect some links that were available in the old doc site into the new versions here.

For example:

http://docs.bitshares.org/tutorials/uia-create-manual.html

Is broken, it should redirect to: https://dev.bitshares.works/en/master/bts_guide/tutorials/mpa-create-manual.html

Others are: https://dev.bitshares.works/en/master/bts_guide/tutorials/mpa-create-manual.html
and https://dev.bitshares.works/en/master/api/blockchain-objects-ids.html

Please note old links are posted in issues, forum posts, etc just as: https://github.com/bitshares/bitshares-core/issues/1111#issuecomment-402136106

It is important to dont lose that traffic where possible.

Thanks.