Sync the template content in nirvana init with nirvana-template-project repo

[iawia002]

Is this a BUG REPORT or FEATURE REQUEST?:

Uncomment only one, leave it on its own line:

/kind bug

/kind feature

Since we have the nirvana-template-project repo, maybe we should sync the template content in nirvana init command with nirvana-template-project repo, and then deprecate nirvana-template-project repo, all nirvana projects can be easily generated by nirvana init xxx.

And since almost all projects have migrated to go mod, maybe we can also drop support for generating project with dep as a package manager, just go mod.

/cc @supereagle @hezhizhen

[hezhizhen]

SGTM

[iawia002]

/assign

[supereagle]

then deprecate nirvana-template-project repo, all nirvana projects can be easily generated by nirvana init xxx

Maybe not all of nirvana-template-project can be covered by nirvana init xx, like Dockerfile and Makefile.

And since almost all projects have migrated to go mod, maybe we can also drop support for generating project with dep as a package manager, just go mod.

LGTM