More docs (#1229)

* Add some more docs

* More docs

* More docs

* Add more docs

crates/nu-protocol/src/syntax_shape.rs

@@ -1,21 +1,33 @@
 use nu_source::{b, DebugDocBuilder, PrettyDebug};
 use serde::{Deserialize, Serialize};
 
+/// The syntactic shapes that values must match to be passed into a command. You can think of this as the type-checking that occurs when you call a function.
 #[derive(Debug, Copy, Clone, Serialize, Deserialize)]
 pub enum SyntaxShape {
+    /// Any syntactic form is allowed
     Any,
+    /// Strings and string-like bare words are allowed
     String,
+    /// Values that can be the right hand side of a '.'
     Member,
+    /// A dotted path to navigate the table
     ColumnPath,
+    /// Only a numeric (integer or decimal) value is allowed
     Number,
+    /// A range is allowed (eg, `1..3`)
     Range,
+    /// Only an integer value is allowed
     Int,
+    /// A filepath is allowed
     Path,
+    /// A glob pattern is allowed, eg `foo*`
     Pattern,
+    /// A block is allowed, eg `{start this thing}`
     Block,
 }
 
 impl PrettyDebug for SyntaxShape {
+    /// Prepare SyntaxShape for pretty-printing
     fn pretty(&self) -> DebugDocBuilder {
         b::kind(match self {
             SyntaxShape::Any => "any shape",