docs: Update _index.md #fix typos

[Piyush-r-bhaskar]

What this PR does / why we need it:

Which issue(s) this PR fixes:
Fixes #

Special notes for your reviewer:

Checklist

• Reviewed the CONTRIBUTING.md guide (required)
• Documentation added
• Tests updated
• Title matches the required conventional commits format, see here
  • Note that Promtail is considered to be feature complete, and future development for logs collection will be in Grafana Alloy. As such, feat PRs are unlikely to be accepted unless a case can be made for the feature actually being a bug fix to existing behavior.
• Changes that require user attention or interaction to upgrade are documented in docs/sources/setup/upgrade/_index.md
• If the change is deprecating or removing a configuration option, update the deprecated-config.yaml and deleted-config.yaml files respectively in the tools/deprecated-config-checker directory. Example PR

[CLAassistant]

All committers have signed the CLA.

[JStickler]

[docs team] LGTM

[JStickler]

@Piyush-r-bhaskar Please sign the CLA so that I can merge this.

[loki-gh-app]

The backport to release-3.1.x failed:

The process '/usr/bin/git' failed with exit code 1

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new branch
git switch --create backport-14608-to-release-3.1.x origin/release-3.1.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x 7965722bb5a4f31cc68d30be0290e529c9aafe96

When the conflicts are resolved, stage and commit the changes:

git add . && git cherry-pick --continue

If you have the GitHub CLI installed:

# Push the branch to GitHub:
git push --set-upstream origin backport-14608-to-release-3.1.x
# Create the PR body template
PR_BODY=$(gh pr view 14608 --json body --template 'Backport 7965722bb5a4f31cc68d30be0290e529c9aafe96 from #14608{{ "\n\n---\n\n" }}{{ index . "body" }}')
# Create the PR on GitHub
echo "${PR_BODY}" | gh pr create --title 'docs: Update _index.md #fix typos (backport release-3.1.x)' --body-file - --label 'size/XS' --label 'type/docs' --label 'backport' --base release-3.1.x --milestone release-3.1.x --web

Or, if you don't have the GitHub CLI installed (we recommend you install it!):

# Push the branch to GitHub:
git push --set-upstream origin backport-14608-to-release-3.1.x

# Create a pull request where the `base` branch is `release-3.1.x` and the `compare`/`head` branch is `backport-14608-to-release-3.1.x`.

# Remove the local backport branch
git switch main
git branch -D backport-14608-to-release-3.1.x