🤔 add FAQ section

Author: krzkaczor

README.md

@@ -36,4 +36,5 @@ Expect more docs soon...
    1. Developing reusable checks
    1. Testing checks
 1. Client API reference
+1. [FAQ](faq.md)
 1. Roadmap

faq.md

@@ -0,0 +1,37 @@
+# FAQ
+
+## Q: How does codechecks relate to DangerJS?
+
+DangerJS is a library, codechecks is a platform. This means many things but most importantly
+DangerJS lacks "memory", you can't compare things that happened on the other commit. This is solved
+by Storage API in codechecks where you upload any artifacts so you can easy access them later.
+
+Another issue is user onboarding process, we provide already existing GitHub app which makes
+onboarding process easy and familiar to our users. You install GitHub app on your repos, you copy
+secret value generated for you and put it into your CI config and you're ready to go. With Danger
+you need to create manually Github bot, generate access keys etc.
+
+Other differences include: we use github checks API that it's way more powerful than putting
+comments in your code. We embrace plugin infrastructure where particular checks (like ex. visual
+regression) are reusable between projects and distributed as NPM packages.
+
+## Q: How is it different from BundleWatcher, Codecov, Percy?
+
+All of these tools do just one particular thing (track build size, code coverage of visual
+regressions) so you need to maintain all of them. They require multiple secrets, repeated
+installations and every tool is configured differently. Sometimes config is not even part of your
+repository but users are forced to click through some UIs. Also, most of them are closed source and
+you can't easily fix things when they are broken.
+
+On the other hand, with codechecks you keep whole configuration in one readable, declarative file
+and all you need to do is install add one secret. Furthermore, everything is open source and you can
+easily tweak particular checks. What's even more inspiring is that you can explore new ideas that
+were never done before like for example type coverage tracking in TypeScript projects.
+
+## Q: What's the business model?
+
+Our whole platform is open source. You can use it and run on your own servers and never pay us any
+cent for this. But to create sustainable development model (ship new features, write new official
+checks, maintain already created ones) we provide SASS product available at codechecks.io.
+codechecks.io is 100% free for any open source projects. We charge only for private repositories. We
+also provide consultancy services and premium support for self hosted instances for additional fees.