README.md in ssmd-0.5.0 vs README.md in ssmd-0.6.0

@@ -38,19 +38,22 @@
 # Output: <speak>hello <emphasis>SSMD</emphasis>!</speak>
 ```
 
 **Note:**
 
-This version is still under development. So far only the following conversions
-described in the specification are implemented:
+This version is still under development. See below which essential SSML constructs are implemented so far:
 
-* Text
-* Emphasis
-* Mark
-* Language
-* Phoneme
-* Prosody
-* Paragraph
+* [x] Text
+* [x] Emphasis
+* [x] Break
+* [x] Language
+* [x] Mark
+* [x] Paragraph
+* [x] Phoneme
+* [x] Prosody
+* [ ] Say-as
+* [x] Substitution
+* [ ] Extensions
 
 ## Development
 
 After checking out the repo, run `bin/setup` to install dependencies. You can run `bin/console` for an interactive prompt that will allow you to experiment.