[Compression] Fix code example (github#1302)

Code example for compression did not work because times were not cast to timestamp without timezone.

Includes some drive-by formatting changes to test out the automatic formatter.

Co-authored-by: Lana Brindley <github@lanabrindley.com>

timescaledb/how-to-guides/compression/manually-compress-chunks.md

@@ -1,4 +1,5 @@
 # Manual compression
+
 In most cases, an automated compression policy is sufficient. However, if you
 want more control over compression, you can also manually compress specific
 chunks.
@@ -8,18 +9,21 @@ Compression alters data on your disk, so always back up before you start.
 </highlight>
 
 ## Compress chunks manually
-Before you start, you need a list of chunks to compress. In this example, we are
-using a hypertable called `example`, and compressing these chunks that are older
-than three days.
+
+Before you start, you need a list of chunks to compress. In this example, you
+use a hypertable called `example`, and compress chunks older than three days.
 
 <procedure>
 
 ### Selecting chunks to compress
+
 1.  At the psql prompt, select all chunks in the table `example` that are older
     than three days:
+
     ```sql
     SELECT show_chunks('example', older_than => INTERVAL '3 days');
     ```
+
 1.  This returns a list of chunks. Take a note of the chunk names:
 
     ||show_chunks|
@@ -29,37 +33,50 @@ than three days.
 
 </procedure>
 
-When you are happy with the list of chunks, you can use the chunk names to manually compress each one.
+When you are happy with the list of chunks, you can use the chunk names to
+manually compress each one.
 
 <procedure>
 
 ### Compressing chunks manually
+
 1.  At the psql prompt, compress the chunk:
+
     ```sql
     SELECT compress_chunk( '<chunk_name>');
     ```
+
 1.  Check the results of the compression with this command:
+
     ```sql
     SELECT *
     FROM chunk_compression_stats('example');
     ```
-    The results show the chunks for the given hypertable, their compression status, and some other statistics:
+
+    The results show the chunks for the given hypertable, their compression
+    status, and some other statistics:
 
     |chunk_schema|chunk_name|compression_status|before_compression_table_bytes|before_compression_index_bytes|before_compression_toast_bytes|before_compression_total_bytes|after_compression_table_bytes|after_compression_index_bytes|after_compression_toast_bytes|after_compression_total_bytes|node_name|
     |---|---|---|---|---|---|---|---|---|---|---|---|
     |_timescaledb_internal|_hyper_1_1_chunk|Compressed|8192 bytes|16 kB|8192 bytes|32 kB|8192 bytes|16 kB|8192 bytes|32 kB||
     |_timescaledb_internal|_hyper_1_20_chunk|Uncompressed||||||||||
-    
+
 1.  Repeat for all chunks you want to compress.
 
 </procedure>
 
 ## Manually compress chunks in a single command
+
 Alternatively, you can select the chunks and compress them in a single command
 by using the output of the `show_chunks` command to compress each one. For
-example, use this command to compress chunks between one and three weeks old 
+example, use this command to compress chunks between one and three weeks old
 if they are not already compressed:
+
 ```sql
-SELECT compress_chunk(i, if_not_compressed => true) 
-  FROM show_chunks('example', now() - INTERVAL '1 week', now() - INTERVAL '3 weeks') i;
+SELECT compress_chunk(i, if_not_compressed => true)
+    FROM show_chunks(
+        'example',
+        now()::timestamp - INTERVAL '1 week',
+        now()::timestamp - INTERVAL '3 weeks'
+    ) i;
 ```