[Docs] Another round of stylistic fixes.

docs/linux_cert_management.md

-**NOTE:** SSL client authentication with personal certificates does not work completely in Linux, see [issue 16830](http://code.google.com/p/chromium/issues/detail?id=16830) and [issue 25241](http://code.google.com/p/chromium/issues/detail?id=25241).
+# Linux Cert Management
 
-# Introduction
+**NOTE:** SSL client authentication with personal certificates does not work
+completely in Linux, see [issue 16830](https://crbug.com/16830) and
+[issue 25241](https://crbug.com/25241).
 
-The easy way to manage certificates is navigate to chrome://settings/search#ssl. Then click on the "Manage Certificates" button. This will load a built-in interface for managing certificates.
+The easy way to manage certificates is navigate to chrome://settings/search#ssl.
+Then click on the "Manage Certificates" button. This will load a built-in
+interface for managing certificates.
 
-On Linux, Chromium uses the [NSS Shared DB](https://wiki.mozilla.org/NSS_Shared_DB_And_LINUX).  If the built-in manager does not work for you then you can configure certificates with the [NSS command line tools](http://www.mozilla.org/projects/security/pki/nss/tools/).
+On Linux, Chromium uses the
+[NSS Shared DB](https://wiki.mozilla.org/NSS_Shared_DB_And_LINUX). If the
+built-in manager does not work for you then you can configure certificates with
+the
+[NSS command line tools](http://www.mozilla.org/projects/security/pki/nss/tools/).
 
-# Details
+## Details
 
-## Get the tools
-  * Debian/Ubuntu: `sudo apt-get install libnss3-tools`
-  * Fedora: `su -c "yum install nss-tools"`
-  * Gentoo: `su -c  "echo 'dev-libs/nss utils' >> /etc/portage/package.use && emerge dev-libs/nss"`  (You need to launch all commands below with the `nss` prefix, e.g., `nsscertutil`.)
-  * Opensuse: `sudo zypper install mozilla-nss-tools`
+### Get the tools
 
+*   Debian/Ubuntu: `sudo apt-get install libnss3-tools`
+*   Fedora: `su -c "yum install nss-tools"`
+*   Gentoo: `su -c  "echo 'dev-libs/nss utils' >> /etc/portage/package.use &&
+    emerge dev-libs/nss"` (You need to launch all commands below with the `nss`
+    prefix, e.g., `nsscertutil`.)
+*   Opensuse: `sudo zypper install mozilla-nss-tools`
 
-## List all certificates
+### List all certificates
 
-`certutil -d sql:$HOME/.pki/nssdb -L`
+    certutil -d sql:$HOME/.pki/nssdb -L
 
-### Ubuntu Jaunty error
+#### Ubuntu Jaunty error
+
 Above (and most commands) gives:
 
-`certutil: function failed: security library: invalid arguments.`
+    certutil: function failed: security library: invalid arguments.
 
 Package version 3.12.3.1-0ubuntu0.9.04.2
 
-## List details of a certificate
+### List details of a certificate
 
-`certutil -d sql:$HOME/.pki/nssdb -L -n <certificate nickname>`
+    certutil -d sql:$HOME/.pki/nssdb -L -n <certificate nickname>
 
-## Add a certificate
+### Add a certificate
 
-`certutil -d sql:$HOME/.pki/nssdb -A -t <TRUSTARGS> -n <certificate nickname> -i <certificate filename>`
+```shell
+certutil -d sql:$HOME/.pki/nssdb -A -t <TRUSTARGS> -n <certificate nickname> \
+-i <certificate filename>
+```
 
-The TRUSTARGS are three strings of zero or more alphabetic
-characters, separated by commas.  They define how the certificate should be trusted for SSL, email, and object signing, and are explained in the [certutil docs](http://www.mozilla.org/projects/security/pki/nss/tools/certutil.html#1034193) or [Meena's blog post on trust flags](https://blogs.oracle.com/meena/entry/notes_about_trust_flags).
+The TRUSTARGS are three strings of zero or more alphabetic characters, separated
+by commas. They define how the certificate should be trusted for SSL, email, and
+object signing, and are explained in the
+[certutil docs](http://www.mozilla.org/projects/security/pki/nss/tools/certutil.html#1034193)
+or
+[Meena's blog post on trust flags](https://blogs.oracle.com/meena/entry/notes_about_trust_flags).
 
-For example, to trust a root CA certificate for issuing SSL server certificates, use
+For example, to trust a root CA certificate for issuing SSL server certificates,
+use
 
-`certutil -d sql:$HOME/.pki/nssdb -A -t "C,," -n <certificate nickname> -i <certificate filename>`
+```shell
+certutil -d sql:$HOME/.pki/nssdb -A -t "C,," -n <certificate nickname> \
+-i <certificate filename>
+```
 
 To import an intermediate CA certificate, use
 
-`certutil -d sql:$HOME/.pki/nssdb -A -t ",," -n <certificate nickname> -i <certificate filename>`
+```shell
+certutil -d sql:$HOME/.pki/nssdb -A -t ",," -n <certificate nickname> \
+-i <certificate filename>
+```
 
 Note: to trust a self-signed server certificate, we should use
 
-`certutil -d sql:$HOME/.pki/nssdb -A -t "P,," -n <certificate nickname> -i <certificate filename>`
+```
+certutil -d sql:$HOME/.pki/nssdb -A -t "P,," -n <certificate nickname> \
+-i <certificate filename>
+```
 
-This should work now, because [NSS bug 531160](https://bugzilla.mozilla.org/show_bug.cgi?id=531160) is claimed to be fixed in a related bug report.  If it doesn't work, then to work around the NSS bug, you have to trust it as a CA using the "C,," trust flags.
+This should work now, because
+[NSS bug 531160](https://bugzilla.mozilla.org/show_bug.cgi?id=531160) is claimed
+to be fixed in a related bug report.  If it doesn't work, then to work around
+the NSS bug, you have to trust it as a CA using the "C,," trust flags.
 
-### Add a personal certificate and private key for SSL client authentication
+#### Add a personal certificate and private key for SSL client authentication
 
 Use the command:
 
-`pk12util -d sql:$HOME/.pki/nssdb -i PKCS12_file.p12`
+    pk12util -d sql:$HOME/.pki/nssdb -i PKCS12_file.p12
 
-to import a personal certificate and private key stored in a PKCS #12 file. The TRUSTARGS of the personal certificate will be set to "u,u,u".
+to import a personal certificate and private key stored in a PKCS #12 file. The
+TRUSTARGS of the personal certificate will be set to "u,u,u".
 
-## Delete a certificate
+### Delete a certificate
 
-`certutil -d sql:$HOME/.pki/nssdb -D -n <certificate nickname>`
+    certutil -d sql:$HOME/.pki/nssdb -D -n <certificate nickname>