add signal (#63)

packages.json

@@ -2464,6 +2464,51 @@
     "repo": "https://github.com/purescript/purescript-sets.git",
     "version": "v3.0.0"
   },
+  "signal": {
+    "dependencies": [
+      "arrays",
+      "bifunctors",
+      "control",
+      "datetime",
+      "distributive",
+      "dom",
+      "eff",
+      "either",
+      "enums",
+      "exceptions",
+      "foldable-traversable",
+      "foreign",
+      "functions",
+      "generics",
+      "globals",
+      "identity",
+      "integers",
+      "invariant",
+      "js-date",
+      "js-timers",
+      "lazy",
+      "lists",
+      "math",
+      "maybe",
+      "media-types",
+      "monoid",
+      "newtype",
+      "nonempty",
+      "nullable",
+      "partial",
+      "prelude",
+      "proxy",
+      "st",
+      "strings",
+      "tailrec",
+      "transformers",
+      "tuples",
+      "unfoldable",
+      "unsafe-coerce"
+    ],
+    "repo": "https://github.com/bodil/purescript-signal.git",
+    "version": "v9.0.0"
+  },
   "st": {
     "dependencies": [
       "eff",