introduce a Book (lighter than Regular) and Think (same as Retina) font weights

Author: kgizdov

FiraCode.glyphs

@@ -121786,12 +121786,54 @@ instanceInterpolations = {
 "4B7A3BAF-EAD8-4024-9BEA-BB1DE86CFCFA" = 0.35417;
 "B67F0F2D-EC95-4CB8-966E-23AE86958A69" = 0.64583;
 };
+name = Retina;
+weightClass = Normal;
+},
+{
+customParameters = (
+{
+name = weightClass;
+value = 350;
+},
+{
+name = "Remove Features";
+value = (
+cpsp
+);
+}
+);
+interpolationWeight = 96;
+instanceInterpolations = {
+"4B7A3BAF-EAD8-4024-9BEA-BB1DE86CFCFA" = 0.35417;
+"B67F0F2D-EC95-4CB8-966E-23AE86958A69" = 0.64583;
+};
 name = Book;
 weightClass = Normal;
 },
 {
 customParameters = (
 {
+name = weightClass;
+value = 450;
+},
+{
+name = "Remove Features";
+value = (
+cpsp
+);
+}
+);
+interpolationWeight = 96;
+instanceInterpolations = {
+"4B7A3BAF-EAD8-4024-9BEA-BB1DE86CFCFA" = 0.35417;
+"B67F0F2D-EC95-4CB8-966E-23AE86958A69" = 0.64583;
+};
+name = Thick;
+weightClass = Normal;
+},
+{
+customParameters = (
+{
 name = "Remove Features";
 value = (
 cpsp