Add Surfactant to tools list (#268)

This adds Surfactant to the tools list, a tool primarily aimed at
generating SBOMs with accurate relationships between files when source
code is not available. CycloneDX is one of the supported output formats,
and will soon be a supported input format (essentially allowing
conversion between formats).

Feedback from users exercising the CycloneDX support will be great --
there's plenty of room for us to improve Surfactant.

Disclaimer -- I am one of the primary authors of Surfactant.

_data/tools.yml

@@ -1900,3 +1900,12 @@
   - analysis
   - transform
   - author
+- name: Surfactant
+  publisher: LLNL
+  description: A modular framework for extracting file information and relationships for filesystems, with an SBOM as the primary output. Also supports limited SBOM merging, editing, and conversion between formats. Several of the supported file types include PE (both native and .NET), ELF, and MSI files.
+  repoUrl: https://github.com/LLNL/Surfactant
+  websiteUrl: https://github.com/LLNL/Surfactant
+  categories:
+  - opensource
+  - transform
+  - library