Lower heading level for sub-headings.

src/features/kernel.md

@@ -16,7 +16,7 @@ In general, we recommend that performance benchmarking be done only with
 `NODEBUG` kernels; see [Benchmarking guidance](../benchmarking/README.md) for
 further details.
 
-# Precompiled kernels in CheriBSD 23.11
+## Precompiled kernels in CheriBSD 23.11
 
 CheriBSD 23.11 ships with a number of precompiled kernels that enable and
 disable various relevant kernel configuration options.
@@ -53,7 +53,7 @@ temporal safety enabled.
 This is expected to change to a pure-capability kernel in future CheriBSD
 releases.
 
-# Identifying the currently booted kernel
+## Identifying the currently booted kernel
 
 The `uname(1)` command prints information on the kernel configuration.
 The following command-line options may be of use:
@@ -72,7 +72,7 @@ benchmarking.
 GENERIC-MORELLO
 ```
 
-# Selecting another kernel using loader.conf
+## Selecting another kernel using loader.conf
 
 You can set the kernel to boot via `/boot/loader.conf` using the variable
 `kernel`.
@@ -97,7 +97,7 @@ After a reboot, `uname(1)` should then report that this is the kernel in use:
 GENERIC-MORELLO-PURECAP
 ```
 
-# Selecting another kernel from the boot loader
+## Selecting another kernel from the boot loader
 
 It is also possible to interactively select a different kernel from the boot
 loader on the video or serial console: