docs/build: improve the structure of the document
docs/build: improve the structure of the document

Break build and execution dependencies. We need to improve documentation
for the configuration step.

Closes #319.

RichardKnop/tsuru,guilhermebr/tsuru,ggarnier/tsuru,cgvarela/tsuru,hcxiong/tsuru,Endika/tsuru,firebitsbr/tsuru,kgrvamsi/tsuru,jblancett/tsuru,kgrvamsi/tsuru,gciotta/tsuru,cezarsa/tsuru,tuxmonteiro/tsuru,firebitsbr/tsuru,guilhermebr/tsuru,gwmoura/tsuru,hcxiong/tsuru,RichardKnop/tsuru,jblancett/tsuru,gwmoura/tsuru,kgrvamsi/tsuru,gciotta/tsuru,4eek/tsuru,ggarnier/tsuru,tsuru/tsuru,ggarnier/tsuru,hugoantunes/tsuru,mderaldo/tsuru,cgvarela/tsuru,ArxdSilva/tsuru,ArxdSilva/tsuru,tsuru/tsuru,gwmoura/tsuru,ggarnier/tsuru,hugoantunes/tsuru,cezarsa/tsuru,4eek/tsuru,jblancett/tsuru,cezarsa/tsuru,tsuru/tsuru,guilhermebr/tsuru,cgvarela/tsuru,ArxdSilva/tsuru,Endika/tsuru,mderaldo/tsuru,tuxmonteiro/tsuru,tsuru/tsuru,guilhermebr/tsuru,hcxiong/tsuru,Endika/tsuru,firebitsbr/tsuru,ArxdSilva/tsuru,gciotta/tsuru,cezarsa/tsuru,mderaldo/tsuru,tuxmonteiro/tsuru,RichardKnop/tsuru,4eek/tsuru