Rename files after property names

src/tail/border/index.scss

@@ -1 +1 @@
-@import "radius";
+@import "border_radius";

src/tail/flex/index.scss

@@ -1,9 +1,9 @@
-@import "direction";
-@import "wrap";
-@import "basis";
+@import "flex_direction";
+@import "flex_wrap";
+@import "flex_basis";
+@import "flex_grow";
 @import "align_content";
 @import "align_items";
 @import "justify_content";
 @import "place_content";
 @import "order";
-@import "grow";

src/tail/font/index.scss

@@ -1,5 +1,5 @@
-@import "family";
-@import "size";
-@import "style";
-@import "weight";
-@import "variant_numeric";
+@import "font_family";
+@import "font_size";
+@import "font_style";
+@import "font_weight";
+@import "font_variant_numeric";