Past branches: adjust header nesting levels

Signed-off-by: Miguel Ojeda <[email protected]>

Author: ojeda

src/Past-branches.md

@@ -1,8 +1,8 @@
-## Past branches
+# Past branches
 
 These branches are unmaintained, archived, deprecated, frozen or do not exist anymore in the repository.
 
-### `rust`
+## `rust`
 
 [`rust`](https://github.com/Rust-for-Linux/linux/tree/rust) was the original branch where development happened for two years before Rust support was merged into the kernel.
 
@@ -14,7 +14,7 @@ Similarly, its [Rust code documentation (2023-03-13)](https://rust-for-linux.git
 
 Changes to this branch landed via [GitHub PRs](https://github.com/Rust-for-Linux/linux/pulls). GitHub Actions was used as a pre-merge CI, compiling the kernel and booting it under QEMU for different toolchains, architectures and configurations. It also checked that some tests passed (e.g. loading sample modules, KUnit tests...) as well as building the PR under Clippy, building the docs, checking `rustfmt`, etc. [KernelCI](https://linux.kernelci.org/job/rust-for-linux/branch/rust/) tests it. Finally, in the past, the [Ksquirrel](Ksquirrel.md) bot checked the PRs sent to it.
 
-### `rust-dev`
+## `rust-dev`
 
 [`rust-dev`](https://github.com/Rust-for-Linux/linux/tree/rust-dev) is an experimental branch for integration purposes. It is a queue for patches that "look good enough".
 
@@ -26,7 +26,7 @@ Its intended use cases are:
 
 Note that this branch may be updated/rebased frequently and it might be gone in the future. Currently, it is on hold.
 
-### Topic branches (`staging/*`)
+## Topic branches (`staging/*`)
 
 These branches were focused on a particular topic and were meant to enable collaboration on code that is targeted for upstreaming but has not reached mainline yet.
 
@@ -36,29 +36,29 @@ Changes to these branches land via GitHub PRs. Nevertheless, contributions shoul
 
 If you are interested in maintaining a new topic branch, then please [contact us](Contact.md). Thank you!
 
-#### `staging/dev`
+### `staging/dev`
 
 [`staging/dev`](https://github.com/Rust-for-Linux/linux/tree/staging/dev) is a branch intended to integrate the other topic branches (similar to the role of `rust-dev` for the main branches).
 
 It is maintained by Danilo Krummrich and Philipp Stanner. Please contact them through [Zulip](Contact.md#zulip-chat).
 
-#### `staging/rust-device`
+### `staging/rust-device`
 
 [`staging/rust-device`](https://github.com/Rust-for-Linux/linux/tree/staging/rust-device) is dedicated to device/driver-related abstractions.
 
 The branch is kept in a compilable state (rebased regularly on top of `rust-next` or mainline). Fixes and features are welcome.
 
 It is maintained by Danilo Krummrich and Philipp Stanner. Please contact them through [Zulip](Contact.md#zulip-chat).
 
-#### `staging/rust-net`
+### `staging/rust-net`
 
 [`staging/rust-net`](https://github.com/Rust-for-Linux/linux/tree/staging/rust-net) is dedicated to networking-related abstractions.
 
 The branch is kept in a compilable state (rebased regularly on top of `rust-next` or mainline). Fixes and features are welcome.
 
 It is maintained by Trevor Gross and Valentin Obst. Please contact them through [Zulip](Contact.md#zulip-chat).
 
-#### `staging/rust-pci`
+### `staging/rust-pci`
 
 [`staging/rust-pci`](https://github.com/Rust-for-Linux/linux/tree/staging/rust-pci) is dedicated to PCI-related abstractions, which are used by e.g. the [NVMe driver](NVMe-driver.md).