treewide: add usage help to various iocsh functions

modules/database/src/template/top/exampleApp/src/_APPNAME_Hello.c

@@ -17,7 +17,17 @@ void hello(const char *name) {
 /* Information needed by iocsh */
 static const iocshArg     helloArg0 = {"name", iocshArgString};
 static const iocshArg    *helloArgs[] = {&helloArg0};
-static const iocshFuncDef helloFuncDef = {"hello", 1, helloArgs};
+static const iocshFuncDef helloFuncDef = {
+    "hello",
+    1,
+    helloArgs,
+#ifdef IOCSHFUNCDEF_HAS_USAGE
+    "Greet the person whose name is given as first argument.\n"
+    "If 'name' is unspecified, greet the world in general.\n\n"
+    "Example: hello\n"
+    "Example: hello stranger\n",
+#endif
+};
 
 /* Wrapper called by iocsh, selects the argument types that hello needs */
 static void helloCallFunc(const iocshArgBuf *args) {

modules/database/src/template/top/exampleApp/src/initTrace.c

@@ -28,7 +28,14 @@ int traceIocInit(void) {
 }
 
 
-static const iocshFuncDef traceInitFuncDef = {"traceIocInit", 0, NULL};
+static const iocshFuncDef traceInitFuncDef = {
+    "traceIocInit",
+    0,
+    NULL,
+    "Setup the 'iocInit' function to trace its different stages.\n"
+    "This function must be called before 'iocInit'.\n\n"
+    "Example: traceIocInit\n",
+};
 static void traceInitFunc(const iocshArgBuf *args) {
     traceIocInit();
 }