use rich-counter instead of headcount

lib.typ

@@ -3,9 +3,13 @@
 #import "@preview/hydra:0.5.1": hydra
 #import "@preview/equate:0.2.1": equate
 #import "@preview/i-figured:0.2.4": reset-counters, show-equation
-#import "@preview/headcount:0.1.0": reset-counter
+#import "@preview/rich-counters:0.2.2": rich-counter
 
-#let mathcounter = counter("mathblocks")  // counter for mathblocks
+// counter for mathblocks
+#let mathcounter = rich-counter(
+  identifier: "mathblocks",
+  inherited_levels: 1
+)
 #let template(
   // personal/subject related stuff
   author: "Stuart Dent",
@@ -179,8 +183,6 @@ show heading: it => {
     it
   }
 }
-// from headcount for theorems
-show heading: reset-counter(mathcounter, levels: 1)
 // ------------------- other settings -------------------
 // Settings for Chapter in the outline
 show outline.entry.where(

template/customization/great-theorems-customized.typ

@@ -1,7 +1,6 @@
 // packages
 #import "../../lib.typ": mathcounter
 #import "@preview/great-theorems:0.1.1": *
-#import "@preview/headcount:0.1.0": *
 
 // local
 #import "colors.typ": *
@@ -10,7 +9,6 @@
   radius: 0.3em,
   inset: 0.8em,
   counter: mathcounter,
-  numbering: dependent-numbering("1.1"),
   breakable: false,
   titlix: title => [(#title):],
 )