revert changes to cron expressions topic

Author: paigecalvert

docs/reference/cron-expressions.md

@@ -33,7 +33,7 @@ The following table lists the required cron fields and supported values:
     <tr>
       <td>Day-of-month</td>
       <td>1 through 31</td>
-      <td>, - * ? </td>
+      <td>, - * ? L W </td>
     </tr>
     <tr>
       <td>Month</td>
@@ -43,14 +43,12 @@ The following table lists the required cron fields and supported values:
     <tr>
       <td>Day-of-week</td>
       <td>1 through 7 or SUN through SAT</td>
-      <td>, - * ?</td>
+      <td>, - * ? L</td>
     </tr>
   </table>
 
 ## Special Characters
 
-Replicated uses the cron v3 Go library. For more information about usage, see [cron](https://pkg.go.dev/github.com/robfig/cron/v3). 
-
 The following table describes the supported special characters:
 
 <table>
@@ -74,6 +72,14 @@ The following table describes the supported special characters:
       <td>Question mark (?)</td>
       <td> Specifies that one or another value can be used. For example, enter <code>5</code> for Day-of-the-month and <code>?</code> for Day-of-the-week to check for updates on the 5th day of the month, regardless of which day of the week it is.</td>
     </tr>
+    <tr>
+      <td>L</td>
+      <td>Specifies the last day of the month or week respectively for the Day-of-month or Day-of-week fields.</td>
+    </tr>
+    <tr>
+      <td>W</td>
+      <td>Specifies the "N-th" occurrence or given day in the month. For example, the second Friday of the month is specified as <code>6#2</code>.</td>
+    </tr>
 </table>
 
 ## Predefined Schedules
@@ -143,11 +149,4 @@ The following examples show valid cron expressions to schedule checking for upda
 
     ```
     30 11 * * *
-    ```
-
-- After 1 hour and 45 minutes, and then every interval following that:
-
-  ```
-  @every 1h45m
-  ```
-
+    `