man: some typesetting and style fixes for recent additions

Mostly start each sentence from a new line.  Also add more pretty
typesetting to cdce(4).

Reviewed by:	imp
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D38501

bin/nproc/nproc.1

@@ -33,7 +33,8 @@ The result is decreased by
 .Ar count ,
 but never below 1.
 .It Fl -version
-Print the current program version and exit. Don't use this option.
+Print the current program version and exit.
+Do not use this option.
 .It Fl -help
 Print usage information and exit.
 .El

share/man/man4/cdce.4

@@ -89,8 +89,12 @@ Mobile
 .Nm
 Network Devices may need a connect command sequence via u3g
 serial command port before they activate the NCM/ECM/ACM network
-interface. Example: echo 'AT^NDISUP=1,1,"internet"' > /dev/cuaU[0].0,
-where "internet" is your providers apn name.
+interface.
+For example:
+.Dl echo 'AT^NDISUP=1,1,"internet"' > /dev/cuaU[0].0
+where
+.Dq internet
+is your providers apn name.
 .Sh HARDWARE
 The following devices are supported by the
 .Nm

share/man/man4/enic.4

@@ -54,10 +54,10 @@ if_enic_load="YES"
 .Sh DESCRIPTION
 The
 .Nm
-driver provides support for Cisco Virtual Interface Card.  Support
-is limited to basic network connectivity.  Media is controlled by the
-NIC itself since there can be multiple virtual PCI NIC devices exposed
-to the PCI bus.
+driver provides support for Cisco Virtual Interface Card.
+Support is limited to basic network connectivity.
+Media is controlled by the NIC itself since there can be multiple
+virtual PCI NIC devices exposed to the PCI bus.
 .Sh HARDWARE
 The
 .Nm