Add more helper methods for facets

[drasticactions]

Addresses #68

This creates additional helper methods for handling creating Facets, given a post text.

var postText = "@drasticactions.dev This is a #test #test of #testing the #FishyFlip #API. https://github.com/drasticactions DAHome. @drasticactions.jp https://github.com/drasticactions/FishyFlip @drasticactions.dev Weee!";
var postHandles = ATHandle.FromPostText(postText);
var feedProfiles = (await atProtocol.Actor.GetProfilesAsync(postHandles)).HandleResult();
var handleFacets = Facet.ForMentions(postText, feedProfiles!.Profiles!);
var hashtagFacets = Facet.ForHashtags(postText);
var uriFacets = Facet.ForUris(postText);
var baseUriFacets = Facet.ForUris(postText, "DAHome", "https://github.com/drasticactions");
var facets = handleFacets.Concat(hashtagFacets).Concat(uriFacets).Concat(baseUriFacets).ToArray();
var result = (await atProtocol.Repo.CreatePostAsync(postText, facets)).HandleResult();

https://bsky.app/profile/drasticactions.xn--q9jyb4c/post/3l7n4vrnoqx2k