Style and typo fixes (#1115)

<!-- ELLIPSIS_HIDDEN -->



> [!IMPORTANT]
> Fixes a typo and updates a heading style in documentation files
`dynamic-types.mdx` and `supported-types.mdx`.
> 
>   - **Style and Typo Fixes**:
> - Corrects typo in `dynamic-types.mdx`: "**output schemas that change
at runtime**" to "**output schema that changes at runtime**".
> - Changes heading "## Primitive types" to "## Primitive Types" in
`supported-types.mdx`.
> 
> <sup>This description was created by </sup>[<img alt="Ellipsis"
src="https://img.shields.io/badge/Ellipsis-blue?color=175173">](https://www.ellipsis.dev?ref=BoundaryML%2Fbaml&utm_source=github&utm_medium=referral)<sup>
for 481db35. It will automatically
update as commits are pushed.</sup>

<!-- ELLIPSIS_HIDDEN -->

docs/docs/calling-baml/dynamic-types.mdx

@@ -2,7 +2,7 @@
 slug: docs/calling-baml/dynamic-types
 ---
 
-Sometimes you have a **output schemas that change at runtime** -- for example if
+Sometimes you have an **output schema that changes at runtime** -- for example if
 you have a list of Categories that you need to classify that come from a
 database, or your schema is user-provided.
 

docs/docs/snippets/supported-types.mdx

@@ -6,7 +6,7 @@ slug: docs/snippets/supported-types
 
 Here's a list of all the types that can be represented in BAML:
 
-## Primitive types
+## Primitive Types
 * `bool`
 * `int`
 * `float`