Use more consistent markup

wiki/src/doc/anonymous_internet/thunderbird.mdwn

@@ -85,5 +85,5 @@ To use <span class="application">Thunderbird</span> in your language, you can
 install the <span class="command">thunderbird-l10n-<span class="command-placeholder">lang</span></span>
 package using the [[Additional Software|doc/first_steps/additional_software]]
 feature. Replace <span class="command-placeholder">lang</span> with the code
-for your language. For example, <code>es</code> for Spanish or <code>de</code>
-for German.
+for your language. For example, <span class="command">es</span> for Spanish or
+<span class="command">de</span> for German.

wiki/src/doc/first_steps/additional_software.mdwn

@@ -78,8 +78,8 @@ Language packs
 - for <span class="application">Thunderbird</span>: <span class="command">thunderbird-l10n-<span class="command-placeholder">lang</span></span>
 
 Replace <span class="command-placeholder">lang</span> with the code for your
-language. For example, <code>es</code> for Spanish or <span>de</span> for
-German.
+language. For example, <span class="command">es</span> for Spanish or
+<span class="command">de</span> for German.
 
 Spell-checking dictionaries
 ---------------------------
@@ -92,8 +92,8 @@ spell-checking by <span class="application">Tor Browser</span>,
 <span class="application">Thunderbird</span>, and many other applications.
 
 Replace <span class="command-placeholder">lang</span> with the code for your
-language. For example, <code>es</code> for Spanish or <span>de</span> for
-German.
+language. For example, <span class="command">es</span> for Spanish or
+<span class="command">de</span> for German.
 
 Installing additional software
 ==============================