refactor(template-typescript): use main script to start app

[codebytere]

• I have read the contribution documentation for this project.
• I agree to follow the code of conduct that this project follows, as appropriate.
• The testsuite passes successfully on my local machine (if applicable).

Summarize your changes:

Fixes up the scripts to set main in package.json to dist instead of baking it into the start script.

[codecov]

Codecov Report

Merging #1345 into master will increase coverage by 28.12%.
The diff coverage is 100%.

@@             Coverage Diff             @@
##           master    #1345       +/-   ##
===========================================
+ Coverage   40.43%   68.56%   +28.12%     
===========================================
  Files           4       70       +66     
  Lines         183     2042     +1859     
  Branches       37      383      +346     
===========================================
+ Hits           74     1400     +1326     
- Misses         96      459      +363     
- Partials       13      183      +170

Impacted Files	Coverage Δ
...ages/template/typescript/src/TypeScriptTemplate.ts	100% <100%> (ø)
packages/maker/snap/src/MakerSnap.ts	100% <0%> (ø)
...es/api/core/src/api/init-scripts/init-directory.ts	93.75% <0%> (ø)
packages/api/core/src/util/index.ts	100% <0%> (ø)
packages/api/core/src/util/publish-state.ts	85.36% <0%> (ø)
packages/utils/async-ora/src/index.ts	100% <0%> (ø)
packages/maker/wix/src/util/author-name.ts	90% <0%> (ø)
packages/plugin/webpack/src/WebpackPlugin.ts	34.85% <0%> (ø)
packages/maker/rpm/src/MakerRpm.ts	94.73% <0%> (ø)
packages/installer/base/src/Installer.ts	75% <0%> (ø)
... and 58 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update abbf031...f8af756. Read the comment docs.

[malept]

I'll merge when tests pass.

[mayeths]

Hey I'm new to electron, and want to figure out how to develop my first electron app using typescript and webpack. Your PR is exactly what I need (thanks!). I tried electron-webpack before but it's hard to write my webpack config since they hide everything so deeply.

Now I use your template to init a empty project, but get stuck with --template=typescript-webpack and --template=typescript arguments. I tried the following steps:

$ yarn create electron-app my-first-electron-app --template=typescript

× Locating custom template: "typescript"
An unhandled error has occurred inside Forge:
Failed to locate custom template: "typescript"
.........

It's failed. Then I see this pull request and try:

$ npm i -g @electron-forge/cli

.........
+ @electron-forge/cli@6.0.0-beta.46

$ electron-forge init my-second-electron-app --template=typescript-webpack

× Locating custom template: "typescript-webpack"
Failed to locate custom template: "typescript-webpack"
Try `npm install -g @electron-forge-template-typescript-webpack`
Error: Failed to locate custom template: "typescript-webpack"
.........

It's also failed. Finally I try typescript template with CLI:

$ electron-forge init my-third-electron-app --template=typescript

√ Checking your system
......... Everything ok here
√ Installing Template Dependencies

It passed. But I can't see anything about typescript in it. The folder looks like this:

Did I make any mistakes? Or maybe it means I should wait until the template release...

electron-forge is awesome. Thanks a million.

[malept]

This template has been released in beta 47, published a few seconds ago.