Update quickstart/_index.md

[clubanderson]

fixed some grammar issue

What this PR does / why we need it:

Which issue(s) this PR fixes:

Fixes #

Does this PR introduce a user-facing change?:

• How are users affected by this change:
• Is this breaking change:
• How to migrate (if breaking change):

[t-kikuc]

@clubanderson
Thank you for your great contribution!

Would you please sign off and pass the DCO check?
cf. https://github.com/pipe-cd/pipecd/pull/4893/checks?check_run_id=24111264579

[t-kikuc]

@clubanderson
Thank you so much for your corrections! 🙏

[EDITED] We'll do the below later, so plz just sign off and pass the DCO.

Would you copy your changes to other versions by the following command?
That's because grammatical corrections should be applied to all versions.
(We're sorry for the unclear process...)

find docs/content/en/*/quickstart/_index.md -type f -exec sed -i '' \
-e 's/on your browser/in your browser/g' \
-e 's/logged in successfully/successfully logging in/g' \
-e 's/at `piped` settings tab/at the `piped` settings tab/g' \
-e 's/will keep running/will run continuously/g' \
-e 's/will not lost/will not be lost/g' \
-e 's/Above are all we need/Above is all that is necessary/g' \
-e 's/deployment would be complete automatically to/deployment is complete and will automatically/g' \
 {} \;

It will copy the changes to:

- docs/content/en/docs-dev/quickstart/_index.md
- docs/content/en/docs-v0.39.x/quickstart/_index.md
- docs/content/en/docs-v0.40.x/quickstart/_index.md
- docs/content/en/docs-v0.41.x/quickstart/_index.md
- docs/content/en/docs-v0.42.x/quickstart/_index.md
- docs/content/en/docs-v0.43.x/quickstart/_index.md
- docs/content/en/docs-v0.44.x/quickstart/_index.md
- docs/content/en/docs-v0.45.x/quickstart/_index.md
- docs/content/en/docs-v0.46.x/quickstart/_index.md

After you do it, I'd like to approve🚀

[t-kikuc]

plz pass DCO 🙏

[clubanderson]

I signed the PR and updated all versions. I do not know what else is blocking this PR now. Please advise

[t-kikuc]

Thank you so much!!!!

[t-kikuc]

@clubanderson
Thank you for signing and coping your changes!!
This PR will be merged after another reviewer approves.
You do not need to do something else:)

[ffjlabo]

Thank you so much :)