move gruvbox module into colors

modules/rainbow.css

@@ -1,4 +1,4 @@
-@import url("https://styles.alv.cx/modules/gruvbox.css");
+@import url("https://styles.alv.cx/modules/colors/gruvbox.css");
 
 :root {
 	--rainbow-duration: 8s;

modules/readmes/colors.txt

@@ -0,0 +1,5 @@
+in the css
+
+@import url("https://styles.alv.cx/modules/colors/<colorscheme>.css");
+
+and use the variables created in the file

modules/readmes/gruvbox.txt

@@ -1,5 +0,0 @@
-in the css
-
-@import url("https://styles.alv.cx/modules/gruvbox.css");
-
-and use the variables created in the file