Added HOW_TO_UPDATE.md

Moved out from README.md

HOW_TO_UPDATE.md

@@ -0,0 +1,64 @@
+# How to update
+
+<br/>
+
+*At the moment of writing, the only supported method is the manual update*
+
+<br/><br/>
+
+## From source
+
+- Run the update script
+  - Linux:
+    - `bash LINUX_build_update.sh`
+  - BSD:
+    - `bash BSD_build_update.sh`
+  - Windows:
+    - run `WIN_build_update_1.bat` as normal user
+    - right-click on `WIN_build_update_2.bat` and select **Run as Administrator**
+  - Mac OS:
+    - `bash MAC_build_update.sh`
+
+<br/><br/>
+
+## From package
+
+### Arch-based distributions
+
+- Pre-made package:
+  - Step in the [Release](https://git.disroot.org/elB4RTO/LogDoctor/releases) page
+  - Download `logdoctor-<VERSION>-x86_64.pkg.tar.zst`
+  - Run `sudo pacman -U logdoctor-<VERSION>-x86_64.pkg.tar.zst`<br/><br/>
+- From the AUR:
+  - Using **yay**:
+    - `yay -S logdoctor`<br/>
+  - Manually:
+    - `git clone https://aur.archlinux.org/logdoctor.git -b master --depth 1`
+    - `cd logdoctor`
+    - `makepkg -sci`
+
+<br/>
+
+### Debian-based distributions
+
+- Pre-made package:
+  - Step in the [Release](https://git.disroot.org/elB4RTO/LogDoctor/releases) page
+  - Download `logdoctor_<VERSION>_amd64.deb`
+  - Run `sudo apt install ./logdoctor_<VERSION>_amd64.deb`<br/><br/>
+
+<br/><br/>
+
+## From binary
+
+- Download a pre-compiled [Release](https://git.disroot.org/elB4RTO/LogDoctor/releases)<br/>
+- Run the update script
+
+<br/><br/>
+
+## As Docker
+
+- Run the update script
+  - Linux:
+    - `bash scripts/DOCKER_build_update.sh`
+
+<br/>