Fixed some typos and formatting issues
Minor corrections
minor #3642 Fixed some typos and formatting issues (javiereguiluz)

This PR was submitted for the master branch but it was merged into the 2.3 branch instead (closes #3642).

Discussion
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Fixed some typos and formatting issues

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | 2.3+
| Fixed tickets | no

Commits
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ce6fc73 Minor corrections
9a3b12f Fixed some typos and formatting issues