Enforce required, optional, and rest positional arguments start with an uppercase and end with a period. (#11285)

# Description

This updates all the positional arguments (except with
`--features=dataframe` or `--features=extra`) to start with an uppercase
letter and end with a period.

Part of #5066, specifically [this
comment](/nushell/nushell/issues/5066#issuecomment-1421528910)

Some arguments had example data removed from them because it also
appears in the examples.

There are other inconsistencies in positional arguments I noticed while
making the tests pass which I will bring up in #5066.

# User-Facing Changes

Positional arguments are now consistent

# Tests + Formatting

- 🟢 `toolkit fmt`
- 🟢 `toolkit clippy`
- 🟢 `toolkit test`
- 🟢 `toolkit test stdlib`

# After Submitting

Automatic documentation updates

crates/nu-cmd-lang/src/core_commands/module.rs

@@ -20,11 +20,11 @@ impl Command for Module {
         Signature::build("module")
             .input_output_types(vec![(Type::Nothing, Type::Nothing)])
             .allow_variants_without_examples(true)
-            .required("module", SyntaxShape::String, "module name or module path")
+            .required("module", SyntaxShape::String, "Module name or module path.")
             .optional(
                 "block",
                 SyntaxShape::Block,
-                "body of the module if 'module' parameter is not a module path",
+                "Body of the module if 'module' parameter is not a module path.",
             )
             .category(Category::Core)
     }