intro.9: minor changes

A correction: 'and' -> 'an'. Plus, several tweaks for brevity or
clarity.

Reviewed by:	mhorne
MFC after:	3 days
Pull Request:	#813

(cherry picked from commit 712fd5a)

share/man/man9/intro.9

@@ -6,7 +6,7 @@
 .\" This manual page was written by Mitchell Horne <mhorne@FreeBSD.org> under
 .\" sponsorship from the FreeBSD Foundation.
 .\"
-.Dd August 2, 2023
+.Dd January 30, 2024
 .Dt INTRO 9
 .Os
 .Sh NAME
@@ -16,7 +16,7 @@
 Welcome to the
 .Fx
 kernel documentation.
-Outside of the source code itself, this set of
+Outside the source code itself, this set of
 .Xr man 1
 pages is the primary resource for information on usage of the numerous
 programming interfaces available within the kernel.
@@ -177,9 +177,10 @@ The kernel interface for file systems is
 File system implementations register themselves with
 .Xr vfsconf 9 .
 .Pp
-The abstract and filesystem-independent representation of a file, directory, or
-other file-like entity within the kernel is the
-.Xr vnode 9 .
+The
+.Xr vnode 9
+is the abstract and filesystem-independent representation of a file,
+directory, or other file-like entity within the kernel.
 .Pp
 The implementation of access control lists for filesystems is described by
 .Xr acl 9 .
@@ -371,7 +372,7 @@ Signals can be sent to processes or process groups using the functions
 described by
 .Xr psignal 9 .
 .Ss Security
-See the generic security overview in
+See the overview in
 .Xr security 7 .
 .Pp
 The basic structure for user credentials is
@@ -397,7 +398,7 @@ see
 .Xr mac 9 .
 .Pp
 Cryptographic services are provided by the OpenCrypto framework.
-This API provides and interface for both consumers and crypto drivers;
+This API provides an interface for both consumers and crypto drivers;
 see
 .Xr crypto 9 .
 .Pp
@@ -409,9 +410,9 @@ and
 The interfaces for declaring loadable kernel modules are described by
 .Xr module 9 .
 .Ss Interrupts
-The machine-independent portion of the interrupt framework supporting the
-registration and execution of interrupt handlers is described by
-.Xr intr_event 9 .
+.Xr intr_event 9
+describes the machine-independent portion of the interrupt framework
+that supports registration and execution of interrupt handlers.
 .Pp
 Software interrupts are provided by
 .Xr swi 9 .
@@ -450,17 +451,16 @@ Kernel sanitizers can perform additional compiler-assisted checks against
 memory use/access.
 These runtimes are capable of detecting difficult-to-identify classes of bugs,
 at the cost of a large overhead.
-Supported is the Kernel Address Sanitizer
-.Xr KASAN 9 ,
-and the Kernel Memory Sanitizer
-.Xr KMSAN 9 .
+The Kernel Address Sanitizer
+.Xr KASAN 9
+and Kernel Memory Sanitizer
+.Xr KMSAN 9
+are supported.
 .Pp
 The
-.Cd LOCK_PROFILING
+.Xr LOCK_PROFILING 9
 kernel config option enables extra code to assist with profiling and/or
-debugging lock performance;
-see
-.Xr LOCK_PROFILING 9 .
+debugging lock performance.
 .Ss Driver Tools
 Defined functions/APIs for specific types of devices.
 .Bl -tag -width "Xr usbdi 9"
@@ -514,6 +514,6 @@ The kernel object implementation is described by
 .Xr man 1 ,
 .Xr style 9
 .Rs
-.%T "The FreeBSD Architecture Handbook"
-.%U "https://docs.freebsd.org/en/books/arch-handbook/"
+.%T The FreeBSD Architecture Handbook
+.%U https://docs.freebsd.org/en/books/arch-handbook/
 .Re