Improved local shell snippet rendering

knowledge base/grep.md

@@ -2,7 +2,7 @@
 
 ## TL;DR
 
-```shell
+```sh
 # base search
 grep 'pattern' path/to/search
 
@@ -39,7 +39,7 @@ For simple searches, you might want to use [pdfgrep].
 Should you need more advanced grep capabilities not incorporated by pdfgrep, you might want to convert the file to text and search there.  
 You can to this using [pdftotext](pdfgrep.md) as shown in this example ([source][stackoverflow answer about how to search contents of multiple pdf files]):
 
-```shell
+```sh
 find /path -name '*.pdf' -exec sh -c 'pdftotext "{}" - | grep --with-filename --label="{}" --color "your pattern"' ';'
 ```
 
@@ -48,7 +48,7 @@ find /path -name '*.pdf' -exec sh -c 'pdftotext "{}" - | grep --with-filename --
 - Standard editions of `grep` run in a single thread; use another executor like
   `parallel` or `xargs` to parallelize grepping multiple files:
 
-  ```shell
+  ```sh
   find . -type f | parallel -j 100% grep 'pattern'
   find . -type f -print0 | xargs -0 -n 1 -P $(nproc) grep 'pattern'
   ```