Update model metadata to set pipeline tag to the new `text-ranking`

Hello!

## Pull Request overview
* Update metadata to set pipeline tag to the new `text-ranking`

## Changes
This is an automated pull request to update the metadata of the model card. We recently introduced the [`text-ranking`](https://huggingface.co/models?pipeline_tag=text-ranking) pipeline tag for models that are used for ranking tasks, and we have a suspicion that this model is one of them.

Feel free to respond if you have questions or concerns.

- Tom Aarsen

README.md

@@ -1,14 +1,15 @@
 ---
 license: mit
-pipeline_tag: sentence-similarity
+pipeline_tag: text-ranking
 tags:
 - sentence-similarity
 widget:
-- source_sentence: "information retrieval"
+- source_sentence: information retrieval
   sentences:
-  - "Information retrieval (IR) in computing and information science is the process of obtaining information system resources that are relevant to an information"
-  - "That is a very happy person"
-  example_title: "information retrieval"
+  - Information retrieval (IR) in computing and information science is the process
+    of obtaining information system resources that are relevant to an information
+  - That is a very happy person
+  example_title: information retrieval
 ---
 
 This model predicts the relevance of a query-document pair.