#179: README update for [beta] TKO builds

[lorikayman]

Close https://github.com/knockout/tko/issues/179

As bescribed there i wanted to detail out these moments at project readme:

• [x] how to import TKO properly, considering different modules
• [x] build process now with esbuild instead of rollup
• [x] clearer basic instructions on monorepo usage for newcomers
• [ ] represent monorepo architecture more transparently, explain tools/* interaction with makefile as they are deeply tied to each other (and test infrastructure) considering tools/* are referred at every inline package -- as up now it takes time to figure it all out despite working with both test runners, bundlers and monorepo managers, -- basically explain how it all sticks together.