Fleshed out Luau Recap for March 2021

docs/_posts/2021-03-29-luau-recap-march-2021.md

@@ -9,16 +9,39 @@ Luau is our new language that you can read more about at [https://roblox.github.
 
 ## Typed variadics
 
+[TODO]
+
 ## Generic functions
 
+[TODO]
+
 ## Typechecking improvements
 
+* Check bodies of methods whose `self` has type `any`
+* More precise types for `debug.*` methods
+* Better typechecking for `Instance:IsA`.
+
 ## Performance improvements
 
-## Debugger improvements
+* Optimized `coroutine.resume`
+  (a 10% speed-up in benchmarks)
+* New implementation of string mutations, which mutates in place rather than copying if there's
+  only one copy of the string buffer (a 20% speedup)
+* New `FASTCALL` specializations, optimizing common cases for methods such as `table.insert`
+  (a 40% speedup)
+* Improved `table.move` performance (often 3x faster!)
 
 ## Library changes
 
+* Added the `debug.info` function which allows retrieving information about stack frames or functions; similarly to `debug.getinfo` from Lua, this accepts an options string that must consist of characters `slnfa`; unlike Lua that returns a table, the function returns all requested values one after another to improve performance.
+
 ## New logo
 
+Luau now has a shiny new logo!
+
+!["New logo!"]({{ site.url }}{{ site.baseurl }}/assets/images/luau.png)
+
 ## Coming soon...
+
+* Better treatment of cyclic requires
+* [Anything else?]