Some documentation corrections.

Author: alexrp

doc/language/lexical-structure/literals.md

@@ -57,12 +57,20 @@ atom-literal ::= ':' (upper-identifier |
 ## String Literal
 
 ```ebnf
-string-literal ::= '"' ([^#xa#xd#x85#x2028#x2029"\] |
-                        string-escape-sequence)* '"'
-string-escape-sequence ::= '\' (string-escape-simple |
-                                string-escape-unicode)
-string-escape-simple ::= [0aAbBeEfFnNrRtTvV"\]
-string-escape-unicode ::= [uU] hexadecimal-digit hexadecimal-digit hexadecimal-digit hexadecimal-digit hexadecimal-digit hexadecimal-digit
+string-literal ::= normal-string-literal |
+                   verbatim-string-literal |
+                   block-string-literal
+```
+
+### Normal String Literal
+
+```ebnf
+normal-string-literal ::= '"' ([^#xa#xd#x85#x2028#x2029"\] |
+                               string-escape-sequence)* '"'
+normal-string-escape-sequence ::= '\' (string-escape-simple |
+                                       string-escape-unicode)
+normal-string-escape-simple ::= [0aAbBeEfFnNrRtTvV"\]
+normal-string-escape-unicode ::= [uU] hexadecimal-digit hexadecimal-digit hexadecimal-digit hexadecimal-digit hexadecimal-digit hexadecimal-digit
 ```
 
 ### Verbatim String Literal

doc/language/types/special/unknown-type.md

@@ -9,6 +9,6 @@ Unlike `any`, however, `unk` only allows a very limited set of operations which
 are safe on all values. In other words, `unk` is the type-safe counterpart to
 `any`.
 
-A value of type `unk` can only be assigned to a location of type `unk`.
+A value of type `unk` can only be assigned to a location of type `unk` or `any`.
 
 <!-- TODO: Describe semantics when checking an unk value's type dynamically. -->