xpass/constants.xml Add tags (#4340)

Author: mmalferov

Diff for: reference/xpass/constants.xml

@@ -6,9 +6,12 @@
 
  <simpara>
   Xpass extension provides various set of constants.
-  Hash methods (CRYPT_PREFIX_) for <function>crypt_gensalt</function> prefix parameter.
-  Error codes (CRYPT_SALT_) returned by <function>crypt_checksalt</function>.
-  Password algorithms (PASSWORD_) for <function>password_hash</function> algo parameter.
+  Hash methods (<constant>CRYPT_PREFIX_<replaceable>*</replaceable></constant>) for
+  <function>crypt_gensalt</function> prefix parameter.
+  Error codes (<constant>CRYPT_SALT_<replaceable>*</replaceable></constant>) returned by
+  <function>crypt_checksalt</function>.
+  Password algorithms (<constant>PASSWORD_<replaceable>*</replaceable></constant>) for
+  <function>password_hash</function> algo parameter.
  </simpara>
 
  <variablelist xml:id="xpass.constants.algo">