feat: 添加内容热重载指令 (#4)

Reviewed-on: #4

YaeBlog.Core/Abstractions/IEssayContentService.cs

@@ -9,5 +9,14 @@ public interface IEssayContentService
 
     public IReadOnlyDictionary<EssayTag, List<BlogEssay>> Tags { get; }
 
-    public bool SearchByUrlEncodedTag(string tag,[NotNullWhen(true)] out List<BlogEssay>? result);
+    public IReadOnlyDictionary<string, BlogHeadline> Headlines { get; }
+
+    public bool TryAddHeadline(string filename, BlogHeadline headline);
+    public bool SearchByUrlEncodedTag(string tag, [NotNullWhen(true)] out List<BlogEssay>? result);
+
+    public bool TryAdd(BlogEssay essay);
+
+    public void RefreshTags();
+
+    public void Clear();
 }