docs: (logs-deletion.md) URL Encode curl command

[mr-karan]

What this PR does / why we need it:

What: Update the cURL command example to URL encode
the match query param

Why: The current cURL command throws this error:

$ curl -X POST \                                                                                                                                        
  'http://localhost:3100/loki/api/admin/delete?match[]={foo="bar"}&start=1591616227&end=1591619692' \                                                    
  -H 'x-scope-orgid: fake'
1:4: parse error: unexpected "="

Checklist

• Documentation added
• Tests updated

[CLAassistant]

All committers have signed the CLA.

[mr-karan]

@KMiller-Grafana Thanks for the review, made the suggested changes.

[KMiller-Grafana]

Thanks! LGTM. I approve.

[Alan01252]

An alternative to this is to use -g

curl -g -X POST \ 'http://127.0.0.1:3100/loki/api/admin/delete?match[]={foo="bar"}&start=1591616227&end=1591619692' \ -H 'x-scope-orgid: 1'

[mr-karan]

Ah TIL. https://explainshell.com/explain?cmd=curl+-g

Yeah, this is a better option.