textops: docs - notes that msg_apply_changes() may be required for multi-part operations

- GH #1719

(cherry picked from commit 5460db2e59341f143d607de744faa8413216afd5)

src/modules/textops/doc/textops_admin.xml

@@ -1638,6 +1638,7 @@ if (starts_with("$rU", "+358"))
 set_body_multipart("test", "text/plain", "delimiter");
 msg_apply_changes();
 append_body_part(...);
+msg_apply_changes();
 
 ...
 
@@ -1690,12 +1691,17 @@ text
 		The core will take care of the last boundary ending "--". Detecting wich one is
 		the last and fixing the others if needed.
 		</para>
+		<para>
+		Note: it may be required that msg_apply_changes() from textopsx module
+		has to be executed if there are other operations over the new body.
+		</para>
 		<example>
 		<title><function>append_body_part</function> usage</title>
 		<programlisting format="linespecific">
 ...
 $var(b) = "7e Od 04 55 75 69 20 4d 61 6b 65 43 61 6c 6c";
 append_body_part("$var(b)", "application/vnd.cirpack.isdn-ext", "signal;handling=required");
+msg_apply_changes();
 ...
 
 # Will append this to the body:
@@ -1721,6 +1727,7 @@ Content-Disposition: signal;handling=required
 ...
 $var(b) = "<info>active</info>";
 append_body_part("$var(b)", "application/xml\r\nX-Header: xyz");
+msg_apply_changes();
 ...
 
 # Will append this to the body:
@@ -1773,12 +1780,17 @@ Content-Disposition: signal;handling=required
 		The core will take care of the last boundary ending "--". Detecting wich one is
 		the last and fixing the others if needed.
 		</para>
+		<para>
+		Note: it may be required that msg_apply_changes() from textopsx module
+		has to be executed if there are other operations over the new body.
+		</para>
 		<example>
 		<title><function>append_body_part_hex</function> usage</title>
 		<programlisting format="linespecific">
 ...
 $var(b) = "6b 61 6d 61 69 6c 69 6f";
 append_body_part_hex("$var(b)", "application/my-custom-ext");
+msg_apply_changes();
 ...
 
 # Will append this to the body:
@@ -1894,11 +1906,16 @@ get_body_part("application/vnd.cirpack.isdn-ext", "$var(hbody)");
 		The core will take care of the last boundary ending "--". Detecting wich one is
 		the last and fixing the others if needed.
 		</para>
+		<para>
+		Note: it may be required that msg_apply_changes() from textopsx module
+		has to be executed if there are other operations over the new body.
+		</para>
 		<example>
 		<title><function>remove_body_part</function> usage</title>
 		<programlisting format="linespecific">
 ...
 remove_body_part("application/vnd.cirpack.isdn-ext");
+msg_apply_changes();
 ...
 </programlisting>
 		</example>