Change log entry for v1.4 and removed some old TODOs

TODO

@@ -4,12 +4,9 @@ MAYBE:
     - Separate syntax group for heading delimiters
     - Syntax highlight and indent "properties"
   - Inline blocks
+    - Try to get text attributes to stack (e.g. underlined text in bold text)
     - Close inline block using same number of starting delimiters.
     - Set a max number of lines to search for end delimiter for bold/italic/etc. to 3 (might not be possible)
-  - TeX:
-    - Hightlight concealed TeX the same as normal text
-    - Try to get text attributes to stack (e.g. underlined text in bold text)
-      - TeX math fragments in bold, italic, etc. text
 
 UNLIKELY:
   - Implement Emacs's abbreviations (e.g. '\<s<TAB>')