add more linux instructions and fix + add to flatpak inst. building

src/download/linux.md

@@ -42,6 +42,29 @@ apk add prismlauncher
 
 <div class="infobox top">
 
+# <img src="https://cdn.freebiesupply.com/logos/large/2x/altlinux-logo-black-and-white.png" height="20"> ALT Linux / <img src="https://static-00.iconduck.com/assets.00/aosc-icon-512x512-tv7gwhzl.png" height="20"> AOSC
+
+Prism Launcher in both distributions may be behind the current version, so please check the version of Prism Launcher in the repositories before installing. See the dropdown menu for details.
+If the launcher is out-of-date, please install the [flatpak](https://flathub.org/apps/details/org.prismlauncher.PrismLauncher) or [build the binary](/wiki/development/build-instructions/#linux) yourself.
+
+<details>
+
+<summary>Advanced - Use at Own Risk</summary>
+
+RPM Packages for ALT Linux on versions [sisyphus](https://packages.altlinux.org/en/sisyphus/srpms/prismlauncher/) and [p10](https://packages.altlinux.org/en/p10/srpms/prismlauncher/) are available for multiple architectures. [Prism Launcher](https://packages.aosc.io/packages/prismlauncher) is also available on AOSC.
+
+Please be warned that versions of PrismLauncher prior to 7.0 have high security vulnerabilities ([GHSA-gq28-qx55-mh2r](https://github.com/PrismLauncher/PrismLauncher/security/advisories/GHSA-gq28-qx55-mh2r) and [GHSA-wxgx-8v36-mj2m](https://github.com/PrismLauncher/PrismLauncher/security/advisories/GHSA-wxgx-8v36-mj2m)), so use these packages at your own risk.
+
+```bash
+sudo apt install prismlauncher
+```
+
+</details>
+
+</div>
+
+<div class="infobox top">
+
 # <img src="https://www.vectorlogo.zone/logos/archlinux/archlinux-icon.svg" height="20"/> Arch Linux / <img src="https://upload.wikimedia.org/wikipedia/commons/3/3e/Manjaro-logo.svg" height="20"/> Manjaro
 
 There are several AUR packages available:  
@@ -241,6 +264,33 @@ zypper install prismlauncher-qt5-nightly
 
 <div class="infobox top">
 
+# <img src="https://upload.wikimedia.org/wikipedia/commons/3/34/Slackware_logo.svg" height="20"> Slackware
+
+Prism Launcher is available on [SlackBuilds](https://slackbuilds.org/repository/15.0/games/PrismLauncher/) maintained by Samuel Young. The package is only available for Slackware version 15.0 (currently)!
+
+*Note: You may need to edit the ```PrismLauncher.SlackBuild``` file and change the VERSION variable to reflect that of the source code, although it is better if you wait for the maintainer to update the SlackBuild file.*
+
+```bash
+# download launcher slackbuild archive
+wget https://slackbuilds.org/slackbuilds/15.0/games/PrismLauncher.tar.gz
+# extract archive
+tar -xpvf PrismLauncher.tar.gz; cd PrismLauncher-*
+# download source specified in PrismLauncher.info, for example for version 7.1:
+wget https://github.com/PrismLauncher/PrismLauncher/releases/download/7.1/PrismLauncher-7.1.tar.gz
+# verify integrity
+md5sum PrismLauncher-*.tar.gz # compare the result with the md5 in PrismLauncher.info
+# enter root environment and grant permissions
+su -l; chmod +x PrismLauncher.SlackBuild
+# build package
+./PrismLauncher.SlackBuild
+# install package (name dependent on version, cpu arch)
+cd /tmp; installpkg PrismLauncher-*.tgz
+```
+
+</div>
+
+<div class="infobox top">
+
 # <img src="https://bitcu.co/en/wp-content/uploads/2020/07/Void_Linux_logo.svg_.png" height="20"> Void Linux
 
 Prism Launcher is available on the official Void repository.

src/wiki/development/build-instructions.md

@@ -134,16 +134,27 @@ The path to the .rpm packages will be printed once the build is complete.
 
 ### Building a Flatpak
 
-You don't need to clone the entire Prism Launcher repo for this; the Flatpak file handles that.
+You don't need to clone the entire Prism Launcher repo for the latest stable version; the Flatpak file handles that. However, cloning the source repository is necessary to build from the latest commit (contains upstream manifest).
 Both `flatpak` and `flatpak-builder` must be installed on your system to proceed.
 
+#### Latest Stable Release
+
 ```bash
-git clone https://github.com/flathub/org.prismlauncher.PrismLauncher
+git clone --recursive https://github.com/flathub/org.prismlauncher.PrismLauncher
 cd org.prismlauncher.PrismLauncher
 # remove --user --install if you want to build without installing
 flatpak-builder --user --install flatbuild org.prismlauncher.PrismLauncher.yml
 ```
 
+#### Latest Commit
+
+```bash
+git clone --recursive https://github.com/prismlauncher/PrismLauncher # source repo - contains upstream manifest
+cd PrismLauncher/flatpak
+# remove --user --install if you want to build without installing
+flatpak-builder --user --install flatbuild org.prismlauncher.PrismLauncher.yml
+```
+
 ### Installing Qt using the installer (optional)
 
 1. Run the Qt installer.