webui: "View rule in capa-rules" results in 404 for some rules

[mike-hunhoff]

e.g. opening the capa rule named "packaged as single-file .NET application" from the webui navigates the URL https://mandiant.github.io/capa/rules/packaged-as-single-file-.net-application/ (return: 400) versus opening the same capa rule from capa-rules which navigates the URL https://mandiant.github.io/capa/rules/packaged%20as%20single-file%20.NET%20application/ (return: 200). It may be an issue that the first URL does not employ URL encoding?