Update LICENSE year

mbostock · mbostock · commit 9507d9c70bf9 · 2021-01-20T16:22:41.000-08:00
diff --git a/LICENSE b/LICENSE
@@ -1,4 +1,4 @@
-Copyright 2018 Observable, Inc.
+Copyright 2018-2021 Observable, Inc.
 
 Permission to use, copy, modify, and/or distribute this software for any purpose
 with or without fee is hereby granted, provided that the above copyright notice

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-Copyright 2018 Observable, Inc.`
	`1`	`+Copyright 2018-2021 Observable, Inc.`
`2`	`2`
`3`	`3`	`Permission to use, copy, modify, and/or distribute this software for any purpose`
`4`	`4`	`with or without fee is hereby granted, provided that the above copyright notice`