[Ceres]: Raw pointers as bytes (#493)

* DataPt should contain bytes() now that we have it

* Fix missing negation in docs

docs/sophia_stdlib.md

@@ -142,7 +142,7 @@ datatype name = Name(address, Chain.ttl, map(string, AENSv2.pointee))
 
 ```
 datatype pointee = AccountPt(address) | OraclePt(address)
-                 | ContractPt(address) | ChannelPt(address) | DataPt(string)
+                 | ContractPt(address) | ChannelPt(address) | DataPt(bytes())
 ```
 
 Note: on-chain there is a maximum length enforced for `DataPt`, it is 1024 bytes.
@@ -425,7 +425,7 @@ Bytes.to_fixed_size(a : bytes()) : option(bytes(n))
 ```
 
 Converts an arbitrary size byte array to a fix size byte array. If `a` is
-`n` bytes, `None` is returned.
+not `n` bytes, `None` is returned.
 
 #### to\_any\_size
 ```