Azure samples not getting rendered correctly

> Please provide us with the following information:
> ---------------------------------------------------------------

### This issue is for a: (mark with an `x`)
```
- [ ] bug report -> please search issues before submitting
- [ ] feature request
- [x] documentation issue or request
- [ ] regression (a behavior that used to work and stopped in a new release)
```

### Minimal steps to reproduce
> In OPS, the following error shows up for the samples from this repo

### Any log messages given by the failure
> Link to OPS build of the samples documentation - [here](https://opbuildstorageprod.blob.core.windows.net/report/2020%5C6%5C1%5C65e4cdd8-6821-d8d1-40c6-4cc6db0beb55%5CCommit%5C202006010628518987-develop%5Cworkflow_report.html?sv=2016-05-31&sr=b&sig=mhKKyl7Lkp%2B2hIfCOiLnUQoKE1UbJ%2ByT%2BvLUxDRDcZg%3D&st=2020-06-01T06%3A32%3A38Z&se=2020-07-02T06%3A37%3A38Z&sp=r)
```
Error User ViolateSchema Azure-Samples/blockchain/blockchain-samples/index.yml

Schema validation failed. Please validate the file and make sure it conforms to schema 'Sample' (https://static.docs.com/ui/latest/schemas/Sample.schema.json): Value "rest" is not defined in enum. Path 'languages[4]'. 06/01/2020 06:30:09
```

### Expected/desired behavior
> I check the [documentation guide](https://review.docs.microsoft.com/en-us/new-hope/information-architecture/metadata/taxonomies?branch=master#dev-lang) to make sure `rest` was declared correctly, but the issue still exists.

### OS and Version?
> Windows 7, 8 or 10. Linux (which distribution). macOS (Yosemite? El Capitan? Sierra?)

### Versions
>

### Mention any other details that might be useful

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> Thanks! We'll be in touch soon.