update doc reference for constraint exclusion feature

doc/pg_partman.md

@@ -213,7 +213,7 @@ RETURNS boolean
  * `p_start_partition` - allows the first partition of a set to be specified instead of it being automatically determined. Must be a valid timestamp (for time-based) or positive integer (for id-based) value. Be aware, though, the actual parameter data type is text. For time-based partitioning, all partitions starting with the given timestamp up to CURRENT_TIMESTAMP (plus `premake`) will be created. For id-based partitioning, only the partition starting at the given value (plus `premake`) will be made. Note that for subpartitioning, this only applies during initial setup and not during ongoing maintenance.
  * `p_default_table` - boolean flag to determine whether a default table is created. Defaults to true.
  * `p_automatic_maintenance` - parameter to set whether maintenance is managed automatically when `run_maintenance()` is called without a table parameter or by the background worker process. Current valid values are "on" and "off". Default is "on". When set to off, `run_maintenance()` can still be called on an individual partition set by passing it as a parameter to the function.  See **run_maintenance** in Maintenance Functions section below for more info.
- * `p_constraint_cols` - an optional array parameter to set the columns that will have additional constraints set. See the **About** section above for more information on how this works and the **apply_constraints()** function for how this is used.
+ * `p_constraint_cols` - an optional array parameter to set the columns that will have additional constraints set. See the [Constraint Exclusion](#constraint-exclusion) section above for more information on how this works and the **apply_constraints()** function for how this is used.
  * `p_template_table` - If you do not pass a value here, a template table will automatically be made for you in same schema that pg_partman was installed to. If you pre-create a template table and pass its name here, then the initial child tables will obtain these properties discussed in the **About** section immediately.
  * `p_jobmon` - allow `pg_partman` to use the `pg_jobmon` extension to monitor that partitioning is working correctly. Defaults to TRUE.
  * `p_date_trunc_interval` - By default, pg_partman's time-based partitioning will truncate the child table starting values to line up at the beginning of typical boundaries (midnight for daily, day 1 for monthly, Jan 1 for yearly, etc). If a partitioning interval that does not fall on those boundaries is desired, this option may be required to ensure the child table has the expected boundaries (especially if you also set `p_start_partition`). The valid values allowed for this parameter are the interval values accepted by PostgreSQL's built-in `date_trunc()` function (day, week, month, etc). For example, if you set a 9-week interval, by default pg_partman would truncate the tables by month (since the interval is greater than one month but less than 1 year) and unexpectedly start on the first of the month in some cases. Set this parameter value to `week`, so that the child table start values are properly truncated on a weekly basis to line up with the 9-week interval. If you are using a custom time interval, please experiment with this option to get the expected set of child tables you desire or use a more typical partitioning interval to simplify partition management.