Un-hardcodes the minimum metabolizable amount (#11362)

code/modules/reagents/Chemistry-Holder.dm

@@ -455,7 +455,7 @@ trans_to_atmos(var/datum/gas_mixture/target, var/amount=1, var/multiplier=1, var
 	total_volume = 0
 	amount_cache.len = 0
 	for(var/datum/reagent/R in reagent_list)
-		if(R.volume < 0.1)
+		if(R.volume < R.custom_metabolism/2) //Used to be 0.1, changing this to custom_metabolism/2 to alter balance as little as possible since the default metabolism is 0.2
 			del_reagent(R.id,update_totals=0)
 		else
 			total_volume += R.volume

html/changelogs/asfabuafsuifaf.yml

@@ -0,0 +1,36 @@
+################################
+# Example Changelog File
+#
+# Note: This file, and files beginning with ".", and files that don't end in ".yml" will not be read.  If you change this file, you will look really dumb.
+#
+# Your changelog will be merged with a master changelog. (New stuff added only, and only on the date entry for the day it was merged.)
+# When it is, any changes listed below will disappear.
+#
+# Valid Prefixes: 
+#   bugfix
+#   wip (For works in progress)
+#   tweak
+#   soundadd
+#   sounddel
+#   rscdel (general deleting of nice things)
+#   rscadd (general adding of nice things)
+#   imageadd
+#   imagedel
+#   spellcheck (typo fixes)
+#   experiment
+#   tgs (TG-ported fixes?)
+#################################
+
+# Your name.
+author: 9600bauds
+
+# Optional: Remove this file after generating master changelog.  Useful for PR changelogs that won't get used again.
+delete-after: True
+
+# Any changes you've made.  See valid prefix list above.
+# There needs to be a space after the - and before the prefix. Don't use tabs anywhere in this file.
+# Also, this gets changed to [] after reading.  Just remove the brackets when you add new shit.
+# If you're using characters such as # ' : - or the like in your changelog, surround the entire change with quotes as shown in the second example. These quotes don't show up on the changelog once it's merged and prevent errors.
+# SCREW ANY OF THIS UP AND IT WON'T WORK.
+changes: 
+- tweak: "Changed the minimum metabolizable reagent amount from a constant 0.1 to the reagent's metabolism rate divided by 2. For nearly all reagents this will mean no change, reagents with a small metabolism rate will stop disappearing at 0.1u, drinks will require 0.2u rather than 0.1u minimum."