docs: modify getting-started.md

[rakshitgondwal]

Signed-off-by: Rakshit Gondwal rakshitgondwal3@gmail.com

Fixed some typo's and some grammatical errors.

[codecov]

Codecov Report

Merging #768 (c2c3fb3) into main (ce6b7f0) will decrease coverage by 0.70%.
The diff coverage is n/a.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #768      +/-   ##
==========================================
- Coverage   57.75%   57.06%   -0.70%     
==========================================
  Files          91       83       -8     
  Lines        7243     6763     -480     
==========================================
- Hits         4183     3859     -324     
+ Misses       2891     2777     -114     
+ Partials      169      127      -42     

Impacted Files	Coverage Δ
klt-cert-manager/kubeutils/secret.go
...anager/controllers/keptnwebhookcontroller/certs.go
...rs/keptnwebhookcontroller/webhook_configuration.go
...okcontroller/keptnwebhookcertificate_controller.go
...llers/keptnwebhookcontroller/certificate_secret.go
klt-cert-manager/kubeutils/query.go
klt-cert-manager/eventfilter/eventfilter.go
klt-cert-manager/kubeutils/certificates.go

Flag	Coverage Δ
klt-cert-manager	?
scheduler	21.17% <ø> (ø)

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[sonarcloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

No Coverage information
No Duplication information

[thschue]

Thank you for this PR! LGTM