fix typos

[innovimax]

Please check if the PR fulfills these requirements:

(Add x between brackets to check.)

• I’ve read contributing guidelines
• I’ve signed and sent the Readium ICLA
• I’m making this pull request against the develop branch
• I’ve updated from the develop branch before proposing this pull request
• I’ve tested the changes for bug fixes and/or features
• I’ve documented new code

What kind of change does this PR introduce? (Bug fix, feature, docs update, other)

DOC UPDATE

What is the current behavior? (You can also link to an open issue here)

What is the new behavior?

Does this PR introduce a breaking change? (What changes might users need to make in their application due to this PR?)

Other information:

[JayPanoz]

@llemeurfr Quick question: for such PRs (e.g. typos, docs, etc.), do we really need the Readium ICLA signed and sent? Or is it just for code?

[llemeurfr]

CSS authoring and documentation authoring must get the same level of IP consideration than code.
But for typo corrections we can get a lighter way of handling things. As this PR only covers typos, I agree that signing the ICLA is not needed.

[JayPanoz]

Ok, since it’s a very minor change to the github template (i.e. administrative), unless someone disagrees, I think we can make an exception and merge the PR into the master branch – besides the corrected template would not be updated if it were merged into develop and would require another one from develop to master.

I’m also going to commit the updated template to the contributing guidelines in the master branch directly (and reflect handling of the ICLA for typos). Then sync the develop branch.

[JayPanoz]

Thanks for catching those typos, @innovimax