Add URL for Remove Halo plug-in in other repo.

utilities/gimp/plug-ins/remove_halo.md

@@ -0,0 +1,49 @@
+# Channel Tools
+
+https://github.com/poikilos/channel_tools.git
+
+## [git] - 2020-02-19
+### Removed
+- This may have worked after additoinal fixes.
+  - https://www.youtube.com/watch?v=YHXX3KuB23Q (outdated)
+  - https://jacksonbates.wordpress.com/2015/09/14/python-fu-6-accepting-user-input/
+```python
+register(
+    "python_fu_remove_halo",
+    "Remove Halo",
+    "Remove alpha",
+    "Jake Gustafson", "Jake Gustafson", "2020",
+    "Remove Halo",  # caption
+    "RGBA",  # RGB* would mean with or without alpha.
+    [
+        (PF_SPINNER, "threshold", "Minimum alpha to fix", 254, (0, 255, 1)),
+        (PF_BOOL, "make_opaque", "Make the fixed parts opaque.", True),
+        (PF_DRAWABLE, "drawable", "Input layer", None),
+    ],
+    [],
+    remove_layer_halo,
+    menu="<Image>/Layer"
+)
+```
+
+- This may be deprecated, even though it matches the docs.
+  - https://www.gimp.org/docs/python/index.html
+```python
+register(
+    "python_fu_remove_halo",
+    "Remove Halo",
+    "Remove Halo (Redo the edge)",
+    "Jake Gustafson",
+    "Jake Gustafson",
+    "2020",
+    "<Image>/Layer",
+    "RGBA",  # RGB* would mean with or without alpha.
+    [
+        (PF_SPINNER, "threshold", "Minimum alpha to fix", 254, (0, 255, 1)),
+        (PF_BOOL, "make_opaque", "Make the fixed parts opaque.", True),
+        (PF_DRAWABLE, "drawable", "Input layer", None),
+    ],
+    [],
+    remove_layer_halo
+)
+```