Unify recommendation on building a bazel project and starting a new project

[strangemonad]

I'm happy to see traction on a tool like Bazelisk. One of the biggest issues I've faced using bazel more widely is a standard, simple way to install Bazel and and keep it up to date.

Related, I love that #84 seems to be getting some love. I left a comment there but want to create a dedicated issue. I'd love to see simplification in the documentation and tooling around the "preferred" way to get going. I'd suggest

1. If a project is already setup, then it could include a wrapper script similar to Gradle's as suggested in #84. I don't have to think, I just clone the project and run the bazel build.
2. If the project isn't already setup to use bazel (or if it's a new project) and I don't have bazel installed, I should be able bootstrap the project (wrapper script and maybe even a WORKSPACE file?) Maybe the Bazel landing page can have instructions to curl an up to date wrapper script + verify the sha?
3. At the very least, the binary installer option (with optional xcode-select instructions as step 1 and a download URL that doesn't even have the version filled in) shouldn't be the first thing I see :) Ideally to the end user, bazel vs bazelisk is more of an internal detail.