[DOC] README.md: Adding documentation to environment variable ODOO_BRANCH
[DOC] README.md: Adding documentation to environment variable ODOO_BRANCH

acsone/maintainer-quality-tools,gurneyalex/maintainer-quality-tools,ERP-Ukraine/maintainer-quality-tools,OCA/maintainer-quality-tools,OCA/maintainer-quality-tools,acsone/maintainer-quality-tools,gurneyalex/maintainer-quality-tools,ERP-Ukraine/maintainer-quality-tools,ERP-Ukraine/maintainer-quality-tools,gurneyalex/maintainer-quality-tools,OCA/maintainer-quality-tools,acsone/maintainer-quality-tools