Update mftf.md

Wrap `--filter` example in code markdown so double dash hopefully isn't inadvertently converted to single dash via some frontend JavaScript magic.

Author: danmooney2

docs/commands/mftf.md

@@ -160,7 +160,7 @@ vendor/bin/mftf generate:tests [option] [<test name>] [<test name>] [--remove]
 | Option | Description|
 | ---| --- |
 | `--config=[<default> or <singleRun> or <parallel>]` | Creates a single manifest file with a list of all tests. The default location is `tests/functional/Magento/FunctionalTest/_generated/testManifest.txt`.<br/> You can split the list into multiple groups using `--config=parallel`; the groups will be generated in `_generated/groups/` like `_generated/groups/group1.txt, group2.txt, ...`.<br/> Available values: `default` (default), `singleRun`(same as `default`), and `parallel`.<br/> Example: `generate:tests --config=parallel`. |
-| `--filter` | Option to filter tests to be generated.<br/>Template: '&lt;filterName&gt;:&lt;filterValue&gt;'.<br/>Existing filter types: severity.<br/>Existing severity values: BLOCKER, CRITICAL, MAJOR, AVERAGE, MINOR.<br/>Example: --filter=severity:CRITICAL|
+| `--filter` | Option to filter tests to be generated.<br/>Template: '&lt;filterName&gt;:&lt;filterValue&gt;'.<br/>Existing filter types: severity.<br/>Existing severity values: BLOCKER, CRITICAL, MAJOR, AVERAGE, MINOR.<br/>Example: `--filter=severity:CRITICAL`|
 | `--force` | Forces test generation, regardless of the module merge order defined in the Magento instance. Example: `generate:tests --force`. |
 | `-i,--time` | Set time in minutes to determine the group size when `--config=parallel` is used. The __default value__ is `10`. Example: `generate:tests --config=parallel --time=15`|
 | `--tests` | Defines the test configuration as a JSON string.|