change readme instructions to run build and run preview

[Pewillia]

(10)

Description

.change readme instructions to run build and run preview, fix spelling

Fixes # (10) change readme instructions to run build and run preview

Type of change

• [ x] Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce.

https://pewillia.github.io/geoview-demo/?config=01-basemap-LCC-TLS.json

Checklist:

• I have build (npm run build) and deploy (npm run deploy) my PR
• I have connected the issues(s) to this PR
• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• [x ] My changes generate no new warnings
• I have created new issue(s) related to the outcome of this PR is needed
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes