Add changelog note about backups

Signed-off-by: Mqrius <Nuntius.Marii@Gmail.com>

CHANGELOG.md

@@ -1,11 +1,13 @@
 # Changelog
 
 ## Unreleased
+### Important note
+- Due to a config file error, the automatic hourly backup has not been running since 0.11.15. So before you update make sure to make a copy of your world in case anything goes wrong! This is generally good advice but extra important right now.
 ### Breaking changes
 - The steam thermal centrifuge now requires a maintenance hatch. It also now requires 480mB steam per tick instead of 64mb, equivalent to how much 8 LV thermal centrifuges would use. It also now only takes 20 seconds instead of 30. It also now actually outputs byproducts like it was supposed to. @Pyritie
 - Single block steam generators are now more expensive to craft, so there isn't such a huge gap between steam, gas, and combustion generators @TomPlop
 - A lot of backend code has been cleaned up and refactored, so there may be duplicate, missing, or incorrect recipes. If you find any, please report them in [our github](https://github.com/TerraFirmaGreg-Team/Modpack-Modern/issues)!
-#### Electric Greenhouse
+### Electric Greenhouse
 - The Electric Greenhouse multiblock has completely changed. It's significantly shorter and slightly narrower too. You can still grow the same things in it, but it no longer has Perfect Overclocking. Instead, it's stronger in LV but starts getting weaker in HV+. @Redeix
 - There's a new IV variant (Hydroponics Facility) which supports parallel hatches and can do any recipe on any planet. @Redeix
 - Added a new Pisciculture Fishery to mid HV which, when properly looped, will improve the Electric Greenhouse further than just fertiliser. It also breeds fish! @Redeix
@@ -74,6 +76,7 @@
 - Fixed the lunchboxes not removing the "cooling" trait when items were removed with the number keys @Thomasx0
 - Digger helmet crafting now correctly consumes the cloth hat (#2770) @Inceitious
 - Fixed an exploit with the schematicannon @Mqrius
+- Fixed backup frequency config @Mqrius
 ### Translation updates
 - Chinese (simplified) @jmecn
 - Russian @Petr211071 + @Nixieeunrare + @Maxiffon