Add Slang (#868)

### Pre-submission checklist:

*Please check each of these after submitting your pull request:*

* [x] Are you including a `repo_url`? You need to pick the single best
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entries](https://github.com/AcademySoftwareFoundation/aswf-landscape#new-entries)
section?
* [x] Have you added the SVG for your logo to `hosted_logos` and
referenced it in the entry in `landscape.yml`?
* [x] Does your logo clearly state the name of the project/product and
follow the other logo
[guidelines](https://github.com/AcademySoftwareFoundation/aswf-landscape#logos)?
* [x] Does your project name match the text on the logo?
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---------

Signed-off-by: CNCF-Bot <[email protected]>
Signed-off-by: John Mertic <[email protected]>
Co-authored-by: CNCF-Bot <[email protected]>

Author: jmertic

hosted_logos/slang.svg

@@ -531,6 +531,13 @@ landscape:
             logo: stratusgfx.svg
             organization:
               name: KTStephano
+          - item:
+            name: Slang
+            homepage_url: https://shader-slang.com/
+            repo_url: https://github.com/shader-slang/slang
+            project_org: https://github.com/shader-slang
+            logo: slang.svg
+            crunchbase: https://www.crunchbase.com/organization/khronos-group-2
       - subcategory:
         name: Queueing and Render Management
         items: