Add descriptor files

jzero generates code based on descriptor files (desc):

• desc/api: api descriptor language, generate http server/client code. User guide
• desc/proto: proto descriptor language, generate grpc server/client code. User guide
• desc/sql: sql descriptor language, generate database code. User guide

Can also generate model code based on configuration:

• model datasource: Generate database code through remote datasource. User guide
• mongo type: Generate mongodb code by specifying mongo type. User guide

Add api file

Will add api file under desc/api folder

# group is test
jzero add api test
# group is test/test1
jzero add api test/test1

Add proto file

Will add proto file under desc/proto folder

# Service is Test
jzero add proto test
# Service is TestTest1
jzero add proto test/test1

Add sql file

Will add sql file under desc/sql folder

# table name is test
jzero add sql test