Add comprehensive RustDocs for all public API items

- Add crate-level docs with usage examples for lib.rs
- Document OllamaClient, OllamaClientBuilder, and all public methods
- Document error module with OllamaError variants and OllamaResult
- Document types module with endpoint mapping table
- Document all types in common, chat, generate, ps, pull, tags, version
- Add doc examples for builders, constructors, and key types
- All 26 doc-tests pass

src/types/pull.rs

@@ -1,15 +1,56 @@
+//! Types for the model pull (download) endpoint (`POST /api/pull`).
+//!
+//! Use [`PullRequest::builder()`] to construct a request and pass it to
+//! [`OllamaClient::pull()`](crate::OllamaClient::pull). The response is
+//! streamed as a sequence of [`PullResponse`] status updates.
+//!
+//! # Examples
+//!
+//! ```no_run
+//! # use ollama_rs::OllamaClient;
+//! # use ollama_rs::types::pull::PullRequest;
+//! # use futures_util::StreamExt;
+//! # async fn run() -> ollama_rs::error::OllamaResult<()> {
+//! let client = OllamaClient::default();
+//! let request = PullRequest::builder("llama3").build();
+//!
+//! let mut stream = client.pull(request);
+//! while let Some(chunk) = stream.next().await {
+//!     println!("{}", chunk?.status);
+//! }
+//! # Ok(())
+//! # }
+//! ```
+
 use serde::{Deserialize, Serialize};
 
+/// A request to download a model from the Ollama registry (`POST /api/pull`).
+///
+/// Construct via [`PullRequest::builder()`].
+///
+/// # Examples
+///
+/// ```
+/// use ollama_rs::types::pull::PullRequest;
+///
+/// let request = PullRequest::builder("llama3")
+///     .stream(true)
+///     .build();
+/// ```
 #[derive(Debug, Serialize, Deserialize)]
 pub struct PullRequest {
+    /// The model name to pull (e.g., `"llama3"`, `"llama3:latest"`).
     pub model: String,
+    /// Allow insecure (HTTP) connections to the registry.
     #[serde(skip_serializing_if = "Option::is_none")]
     pub insecure: Option<bool>,
+    /// Whether to stream status updates. When `None`, the server default applies.
     #[serde(skip_serializing_if = "Option::is_none")]
     pub stream: Option<bool>,
 }
 
 impl PullRequest {
+    /// Returns a [`PullRequestBuilder`] for the given model name.
     pub fn builder<M: Into<String>>(model: M) -> PullRequestBuilder {
         PullRequestBuilder {
             pull_request: PullRequest {
@@ -21,28 +62,37 @@ impl PullRequest {
     }
 }
 
+/// A builder for constructing a [`PullRequest`].
+///
+/// Obtain a builder via [`PullRequest::builder()`].
 pub struct PullRequestBuilder {
     pull_request: PullRequest,
 }
 
 impl PullRequestBuilder {
+    /// Sets whether to stream status updates.
     pub fn stream(mut self, stream: bool) -> Self {
         self.pull_request.stream = Some(stream);
         self
     }
 
+    /// Allows insecure (HTTP) connections to the model registry.
     pub fn insecure(mut self, insecure: bool) -> Self {
         self.pull_request.insecure = Some(insecure);
         self
     }
 
+    /// Consumes the builder and returns the configured [`PullRequest`].
     pub fn build(self) -> PullRequest {
         self.pull_request
     }
 }
 
+/// A streaming status update from the model pull operation.
 #[derive(Debug, Serialize, Deserialize)]
 pub struct PullResponse {
+    /// A human-readable status message (e.g., `"pulling manifest"`,
+    /// `"downloading sha256:..."`).
     pub status: String,
 }