Fix typo in developer_docs/installation.md title

[Eswaraprasadp]

Fixes #1344

I have verified that this pull request:

• has no linting errors (npm run lint)
• is from a uniquely-named feature branch and has been rebased on top of the latest master. (If I was asked to make more changes, I have made sure to rebase onto master then too)
• is descriptively named and links to an issue number, i.e. Fixes #123

[andrewn]

Thanks for opening this PR. I think the title should stay the same because it makes it clear that the instructions are for development, not production installation.