sync docs with code

Author: Mukulyadav2004

man/data.table-condition-classes.Rd

@@ -5,14 +5,21 @@
 \code{data.table} provides specific condition classes for common operations, making it easier to handle conditions programmatically. This is particularly useful when writing robust code or packages that use \code{data.table}. Relying on the exact text of condition messages is fragile (it is not uncommon to change the wording slightly, or for the user's session not to be in English); prefer using the signal class where possible.
 }
 \details{
-\subsection{Available error Classes}{
-\code{data.table} provides four specific error classes:
+\subsection{Available Condition Classes}{
+\code{data.table} provides four specific condition classes:
 
+Error Classes:
 \itemize{
   \item \code{dt_missing_column_error}: When referencing columns that don't exist
   \item \code{dt_invalid_input_error}: When providing invalid input types or empty required arguments
   \item \code{dt_unsortable_type_error}: When trying to sort/key unsupported types
   \item \code{dt_join_type_mismatch_error}: When column types are incompatible in joins/set operations
+  \item \code{dt_invalid_let_error}: When using assignment operators incorrectly
+}
+
+Warning Classes:
+\itemize{
+  \item \code{dt_missing_fun_aggregate_warning}: When aggregation function is missing in operations that require it
 }
 }