Support for tsconfig paths in monorepos

[bennycode]

Project:

• /tsconfig.json - root tsconfig, has path mappings such as @MyLib -> /libs/mylib/src/index.ts
• /libs/*
• /libs/mylib/tsconfig.json lib tsconfig extends root one and has an include field for src/*
• /libs/mylib/src/*
• /apps/myapp/tsconfig.json app tsconfig extends root one and has an include field for src/*
• /apps/myapp/src/*

Currently sourceFile.getProject() from ts-morph to locate TS configs. The sourceFile should be a .d.ts file to properly find references from co-located packages: dsherret/ts-morph#1242 (comment)