chore: add an FAQ

FAQ.md

@@ -0,0 +1,40 @@
+# FAQ
+
+**Why is flatpak included? Should I use flatpak?**
+
+https://github.com/secureblue/secureblue/issues/125#issuecomment-1859610560
+
+**My fans are really loud, is this normal?**
+
+During rpm-ostree operations, it's normal. Outside of that:
+
+- Make sure you followed the nvidia steps in the readme if you're using nvidia.
+- Make sure you're using a `laptop` image if you're using a laptop.
+- Make sure you're using an `asus` image if you're using asus.
+
+**Should I use firejail?**
+
+[No](https://madaidans-insecurities.github.io/linux.html#firejail), use `bubblejail`` if there's no flatpak available for an app. 
+
+**An app I use won't start due to a malloc issue. How do I fix it?**
+
+Override `LD_PRELOAD` for that app. For flatpaks, this is as simple as removing the environment variable via Flatseal.
+
+**On secureblue half of my CPU cores are gone. Why is this?**
+
+`mitigations=auto,nosmt` is set on secureblue. This means that if your CPU is vulnerable to attacks that utilize [Simultaneous Multithreading](https://en.wikipedia.org/wiki/Simultaneous_multithreading), SMT will be disabled.
+
+**Should I use a userns image or not? What's the difference?**
+
+[USERNS](USERNS.md)
+
+**How do I install `x`?**
+
+1. Check if it's already installed using `rpm -qa | grep x`
+2. Check if there's a flatpak available at https://flathub.org
+3. Consider using distrobox or nix to install it
+4. Layer it using `rpm-ostree install`, as a last option
+
+**Another security project has a feature that's missing in secureblue, can you add it?**
+
+First check if the README already has an equivalent or better feature. If it doesn't, open a new github issue.

README.md

@@ -53,6 +53,10 @@ For more info on uBlue, check out the [uBlue homepage](https://universal-blue.or
 
 If you want to add your own customizations on top of secureblue, you are advised strongly against forking. Instead, create a repo for your own image by using [startingpoint](https://github.com/ublue-os/startingpoint), then change your `base-image` to a secureblue image. This will allow you to apply your customizations to secureblue in a concise and maintainable way, without the need to constantly sync with upstream. 
 
+## FAQ
+
+[FAQ](FAQ.md)
+
 ## Installation
 
 Have a look at [PREINSTALL-README](PREINSTALL-README.md) before proceeding.