improve docs (#427)

git-repository/src/revision/mod.rs

@@ -12,6 +12,7 @@ pub use walk::iter::Walk;
 pub mod spec;
 
 /// The specification of a revision as parsed from a revision specification like `HEAD@{1}` or `v1.2.3...main`.
+/// It's typically created by [`repo.rev_parse()`][crate::Repository::rev_parse()].
 ///
 /// See the [official git documentation](https://git-scm.com/docs/git-rev-parse#_specifying_revisions) for reference on how
 /// to specify revisions and revision ranges.

git-repository/src/revision/spec/parse/mod.rs

@@ -13,6 +13,8 @@ pub mod error;
 
 impl<'repo> Spec<'repo> {
     /// Parse `spec` and use information from `repo` to resolve it, using `opts` to learn how to deal with ambiguity.
+    ///
+    /// Note that it's easier and to use [`repo.rev_parse()`][Repository::rev_parse()] instead.
     pub fn from_bstr<'a>(spec: impl Into<&'a BStr>, repo: &'repo Repository, opts: Options) -> Result<Self, Error> {
         let mut delegate = Delegate::new(repo, opts);
         match git_revision::spec::parse(spec.into(), &mut delegate) {

git-repository/src/revision/walk.rs

@@ -3,7 +3,8 @@ use git_odb::FindExt;
 
 use crate::{revision, Repository};
 
-/// A platform to traverse the revision graph by adding starting points as well as points which shouldn't be crossed.
+/// A platform to traverse the revision graph by adding starting points as well as points which shouldn't be crossed,
+/// returned by [`Repository::rev_walk()`].
 pub struct Platform<'repo> {
     pub(crate) repo: &'repo Repository,
     pub(crate) tips: Vec<ObjectId>,