Investigate implicit excludes

Today, TypeScript will implicitly set `exclude` to `./node_modules` and something like `.*/**/*` to avoid dot files. Unfortunately, there are two problems I believe I've found from chatting with users. First, users often end up setting `exclude` which overrides the defaults. This often means that users accidentally over-include files, and that can cause performance issues. Next, these defaults don't work out well enough, and end up going a bit off the rails in certain scenarios. For example, consider the following `.js` monorepo. ``` packages +- package-aaa | +- node_modules <- the cute tiny 10MB node_modules | +- jsconfig.json +- node_modules <- the slightly bigger 10GB node_modules shared by each package ``` Notice that `jsconfig.json` or not, one of these `node_modules` is going to be crawled through unless `exclude` is set appropriately. And regardless of whether `exclude` is implicitly or explicitly on, it's usually wrong. In this case, it should (probably) be `**/node_modules/**/*`. For example, check out https://github.com/IBM/report-toolkit/pull/44/files What I'm suggesting is to harden `exclude` to **always** contain the following paths regardless of whether `exclude` is set. * `**/node_modules/**/*` * `.*/**` To disable this, users will have to turn off a setting like `enableImplicitExcludePatterns`.