fix some typos in manifolds/

[fchapoton]

CC: @egourgoulhon

Component: documentation

Author: Frédéric Chapoton

Branch/Commit: b360173

Reviewer: Samuel Lelièvre

Issue created by migration from https://trac.sagemath.org/ticket/31202

[fchapoton]

Branch: u/chapoton/31202

[fchapoton]

New commits:

d97cda5	fix typos and returns in geometry/polyhedron
f943bb8	fix some typos in manifolds/

[fchapoton]

Commit: f943bb8

[sagetrac-git]

Changed commit from f943bb8 to b360173

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

b360173

fix some typos in manifolds

[slel]

Reviewer: Samuel Lelièvre

[slel]

comment:3

Ok.

[egourgoulhon]

comment:4

Thanks Frédéric! (and Samuel for the review).