release: add configuration for cargo-about

cargo-about is a tool from Embark that walks cargo dependencies for all
third party licenses. Include its configuration file and a template to
generate a third party license file.

Author: juped

about.hbs

@@ -0,0 +1,22 @@
+Third Party Licenses
+
+Overview of licenses:
+
+{{#each overview}}
+{{{name}}} ({{count}})
+{{/each}}
+
+All license text:
+
+{{#each licenses}}
+{{{name}}}
+
+Used by:
+
+{{#each used_by}}
+{{crate.name}} {{crate.version}}
+<{{#if crate.repository}}{{crate.repository}}{{else}}https://crates.io/crates/{{crate.name}}{{/if}}>
+{{/each}}
+
+{{{text}}}
+{{/each}}

about.toml

@@ -0,0 +1,17 @@
+accepted = [
+    "MIT",
+    "0BSD",
+    "ISC",
+    "Unlicense",
+    "BSD-2-Clause",
+    "BSD-3-Clause",
+    "CC0-1.0",
+    "MPL-2.0",
+    "GPL-3.0",
+    "OSL-3.0",
+    "OpenSSL",
+    "Unicode-DFS-2016",
+    "Apache-2.0 WITH LLVM-exception",
+    "Apache-2.0",
+    "NOASSERTION",
+]