heading level and doc for masonry readme (#770)

Update the Masonry readme with documentation on how it is generated and
change the heading level to be consistent with Color

.github/workflows/ci.yml

@@ -98,7 +98,7 @@ jobs:
 
       - name: cargo rdme masonry
         run: |
-          cargo rdme --check --workspace-project=masonry
+          cargo rdme --check --heading-base-level=0 --workspace-project=masonry
 
       - name: cargo rdme tree_arena
         run: |

masonry/README.md

@@ -14,6 +14,13 @@
 
 </div>
 
+<!-- We use cargo-rdme to update the README with the contents of lib.rs.
+To edit the following section, update it in lib.rs, then run:
+cargo rdme --workspace-project=color --heading-base-level=0
+Full documentation at https://github.com/orium/cargo-rdme -->
+
+<!-- Intra-doc links used in lib.rs should be evaluated here.
+See https://linebender.org/blog/doc-include/ for related discussion. -->
 [tracing_tracy]: https://crates.io/crates/tracing-tracy
 
 <!-- cargo-rdme start -->

masonry/src/lib.rs

@@ -12,7 +12,7 @@
 //! Masonry can currently be considered to be in an alpha state.
 //! Lots of things need improvements, e.g. text input is janky and snapshot testing is not consistent across platforms.
 //!
-//! # Example
+//! ## Example
 //!
 //! The to-do-list example looks like this:
 //!
@@ -77,7 +77,7 @@
 //!
 //! For more information, see [the documentation module](crate::doc).
 //!
-//! ## Crate feature flags
+//! ### Crate feature flags
 //!
 //! The following feature flags are available:
 //!