README: add infos on yocto build etc

Change-Id: I6c2ccc7698c2e7945d3810364d86a5afad050722
README: add prerequisites

Change-Id: Ia0cf926691196dea36773264860d6fcbe45b9dfe
README: update buiig section

Change-Id: If235ff36b0e23a9d43f740a96fc72d1795563701
Yocto: add config layer

Change-Id: If677790c08c97fc4eb6c46b22b1691b6508010e9
README.md: add gettext installation otherwise build fails

Change-Id: Ifdc6a2e54344eaaedeaba57d44589f6cd4a99e18
yoctoembedded.xml: change templates location and name

Change-Id: Ifcc0f877da49a65015a3ac4e680ea0148f0bf9e5
Integrate changes

Change-Id: I13d8ec0ef39102beb5d1545001a1216ecccde4c7