Add recipes

recipes/wip/shells/brush/recipe.toml

+#TODO not compiled or tested
+[source]
+git = "https://github.com/reubeno/brush"
+[build]
+template = "custom"
+script = """
+cookbook_cargo_packages brush-shell
+"""

recipes/wip/web/gosub/recipe.toml

+#TODO not compiled or tested
+[source]
+git = "https://github.com/gosub-browser/gosub-engine"
+[build]
+template = "custom"
+script = """
+cookbook_cargo --bin gosub-parser css3-parser renderer \
+style-parser
+"""