docs: Update compression-methods.md (#3799)

Fix Delta encoding examples in "About compression" page

Signed-off-by: Enrico Stefanel <me@enst.it>
Co-authored-by: Iain Cox <iain@timescale.com>

use-timescale/compression/compression-methods.md

@@ -50,16 +50,16 @@ this:
 |time|cpu|mem_free_bytes|temperature|humidity|
 |-|-|-|-|-|
 |2023-04-01 10:00:00|82|1,073,741,824|80|25|
-|2023-04-01 10:05:00|98|858,993,459|81|25|
-|2023-04-01 10:05:00|98|858,904,583|81|25|
+|2023-04-01 10:00:05|98|858,993,459|81|25|
+|2023-04-01 10:00:10|98|858,904,583|81|25|
 
 With delta encoding, you only need to store how much each value changed from the
 previous data point, resulting in smaller values to store. So after the first
 row, you can represent subsequent rows with less information, like this:
 
 |time|cpu|mem_free_bytes|temperature|humidity|
 |-|-|-|-|-|
-|2020-04-01 10:00:00|82|1,073,741,824|80|25|
+|2023-04-01 10:00:00|82|1,073,741,824|80|25|
 |5 seconds|16|-214,748,365|1|0|
 |5 seconds|0|-88,876|0|0|
 
@@ -86,7 +86,7 @@ Applied to the example dataset from earlier, delta-of-delta encoding results in
 |-|-|-|-|-|
 |2020-04-01 10:00:00|82|1,073,741,824|80|25|
 |5 seconds|16|-214,748,365|1|0|
-|0|0|-88,876|0|0|
+|0 seconds|0|-88,876|0|0|
 
 In this example, delta-of-delta further compresses 5 seconds in the time column
 down to 0 for every entry in the time column after the second row, because the