Write about more filter types

go/blog/blog.yaml

@@ -88,3 +88,22 @@
            - "stuff:with-interesting!-characters"
  tags: [tags, feature, announcement, "author:lu"]
  type: text
- title: Filters!  (More of them)
  content: |
    Let's write more filters.  Apart from the `tag` filter that we
    already have.
    Some ideas:
    - `title`: filter by text occurring in the title
    - `post`: filter a specific post by id (or multiple?)
    - `type`: filter by post type
    All of them will work similar to the existing `tag` filter, i.e.
    they can be used as links and will appear in the history.
    If we want to be fancy, we might implement combining filters using
    `and`.
  date: 2016-09-26
  tags: [ideas, feature, "author:lu"]
  type: text