Fix broken link in TGIS_README.md (#9)

The title is self explanatory :)

Signed-off-by: Daniele Zonca <[email protected]>

TGIS_README.md

@@ -2,7 +2,7 @@
 
 This fork attempts to remain aligned with the vLLM repo as much as possible,
 while also containing a set of permanent changes to add:
-- A TGIS api adapter layer (see [TGIS](github.com/IBM/text-generation-inference))
+- A TGIS api adapter layer (see [TGIS](https://github.com/IBM/text-generation-inference))
 - A RedHat UBI-based Docker image delivery
 
 Given the fast pace of vLLM development, we also provide builds that include yet-to-be-merged