Formatting: use markdown lists in 'one of' lists (#726)

* Use markdown line breaks in 'one of' lists

* Move from linebreaks to bullets

Author: benjie

spec/Appendix B -- Grammar Summary.md

@@ -60,13 +60,13 @@ NameContinue ::
   - `_`
 
 Letter :: one of
-  `A` `B` `C` `D` `E` `F` `G` `H` `I` `J` `K` `L` `M`
-  `N` `O` `P` `Q` `R` `S` `T` `U` `V` `W` `X` `Y` `Z`
-  `a` `b` `c` `d` `e` `f` `g` `h` `i` `j` `k` `l` `m`
-  `n` `o` `p` `q` `r` `s` `t` `u` `v` `w` `x` `y` `z`
+  - `A` `B` `C` `D` `E` `F` `G` `H` `I` `J` `K` `L` `M`
+  - `N` `O` `P` `Q` `R` `S` `T` `U` `V` `W` `X` `Y` `Z`
+  - `a` `b` `c` `d` `e` `f` `g` `h` `i` `j` `k` `l` `m`
+  - `n` `o` `p` `q` `r` `s` `t` `u` `v` `w` `x` `y` `z`
 
 Digit :: one of
-  `0` `1` `2` `3` `4` `5` `6` `7` `8` `9`
+  - `0` `1` `2` `3` `4` `5` `6` `7` `8` `9`
 
 IntValue :: IntegerPart [lookahead != {Digit, `.`, NameStart}]
 
@@ -314,24 +314,24 @@ DirectiveLocation :
   - TypeSystemDirectiveLocation
 
 ExecutableDirectiveLocation : one of
-  `QUERY`
-  `MUTATION`
-  `SUBSCRIPTION`
-  `FIELD`
-  `FRAGMENT_DEFINITION`
-  `FRAGMENT_SPREAD`
-  `INLINE_FRAGMENT`
-  `VARIABLE_DEFINITION`
+  - `QUERY`
+  - `MUTATION`
+  - `SUBSCRIPTION`
+  - `FIELD`
+  - `FRAGMENT_DEFINITION`
+  - `FRAGMENT_SPREAD`
+  - `INLINE_FRAGMENT`
+  - `VARIABLE_DEFINITION`
 
 TypeSystemDirectiveLocation : one of
-  `SCHEMA`
-  `SCALAR`
-  `OBJECT`
-  `FIELD_DEFINITION`
-  `ARGUMENT_DEFINITION`
-  `INTERFACE`
-  `UNION`
-  `ENUM`
-  `ENUM_VALUE`
-  `INPUT_OBJECT`
-  `INPUT_FIELD_DEFINITION`
+  - `SCHEMA`
+  - `SCALAR`
+  - `OBJECT`
+  - `FIELD_DEFINITION`
+  - `ARGUMENT_DEFINITION`
+  - `INTERFACE`
+  - `UNION`
+  - `ENUM`
+  - `ENUM_VALUE`
+  - `INPUT_OBJECT`
+  - `INPUT_FIELD_DEFINITION`

spec/Section 2 -- Language.md

@@ -201,13 +201,13 @@ NameContinue ::
   - `_`
 
 Letter :: one of
-  `A` `B` `C` `D` `E` `F` `G` `H` `I` `J` `K` `L` `M`
-  `N` `O` `P` `Q` `R` `S` `T` `U` `V` `W` `X` `Y` `Z`
-  `a` `b` `c` `d` `e` `f` `g` `h` `i` `j` `k` `l` `m`
-  `n` `o` `p` `q` `r` `s` `t` `u` `v` `w` `x` `y` `z`
+  - `A` `B` `C` `D` `E` `F` `G` `H` `I` `J` `K` `L` `M`
+  - `N` `O` `P` `Q` `R` `S` `T` `U` `V` `W` `X` `Y` `Z`
+  - `a` `b` `c` `d` `e` `f` `g` `h` `i` `j` `k` `l` `m`
+  - `n` `o` `p` `q` `r` `s` `t` `u` `v` `w` `x` `y` `z`
 
 Digit :: one of
-  `0` `1` `2` `3` `4` `5` `6` `7` `8` `9`
+  - `0` `1` `2` `3` `4` `5` `6` `7` `8` `9`
 
 GraphQL Documents are full of named things: operations, fields, arguments,
 types, directives, fragments, and variables. All names must follow the same

spec/Section 3 -- Type System.md

@@ -1786,27 +1786,27 @@ DirectiveLocation :
   - TypeSystemDirectiveLocation
 
 ExecutableDirectiveLocation : one of
-  `QUERY`
-  `MUTATION`
-  `SUBSCRIPTION`
-  `FIELD`
-  `FRAGMENT_DEFINITION`
-  `FRAGMENT_SPREAD`
-  `INLINE_FRAGMENT`
-  `VARIABLE_DEFINITION`
+  - `QUERY`
+  - `MUTATION`
+  - `SUBSCRIPTION`
+  - `FIELD`
+  - `FRAGMENT_DEFINITION`
+  - `FRAGMENT_SPREAD`
+  - `INLINE_FRAGMENT`
+  - `VARIABLE_DEFINITION`
 
 TypeSystemDirectiveLocation : one of
-  `SCHEMA`
-  `SCALAR`
-  `OBJECT`
-  `FIELD_DEFINITION`
-  `ARGUMENT_DEFINITION`
-  `INTERFACE`
-  `UNION`
-  `ENUM`
-  `ENUM_VALUE`
-  `INPUT_OBJECT`
-  `INPUT_FIELD_DEFINITION`
+  - `SCHEMA`
+  - `SCALAR`
+  - `OBJECT`
+  - `FIELD_DEFINITION`
+  - `ARGUMENT_DEFINITION`
+  - `INTERFACE`
+  - `UNION`
+  - `ENUM`
+  - `ENUM_VALUE`
+  - `INPUT_OBJECT`
+  - `INPUT_FIELD_DEFINITION`
 
 A GraphQL schema describes directives which are used to annotate various parts
 of a GraphQL document as an indicator that they should be evaluated differently