Remove 150 character limit for course short description

[samuelallan72]

The course short description field has a maxlength in the frontend of 150 characters:

frontend-app-authoring/src/schedule-and-details/introducing-section/index.jsx

Line 104 in 1b537c3

maxLength={150}

However, the backend does not enforce this 150 character limit, and the frontend help text - "Limit to ~150 characters." - suggests it's only a guideline.

So this maxlength could be removed.

Ref. openedx/openedx-demo-course#72

[sarina]

I'm in favor of this from a product perspective - it would be a helpful change. Copying what I wrote on the other issue:

I would recommend that an issue is opened on frontend-app-authoring to either increase or remove the hard character limit. 150 is extremely restrictive, that's the limit for a talk title on Sessionize. The short description of a talk is limited 500 characters, just for reference - and that works fine on the mobile app view. This doesn't feel like a breaking change that requires much product input, I would advocate for either a 500 character limit, a configurable limit, or no limit.

150 characters simply seems like a holdover from edX 2013 (when they last used the built-in catalog) and was made for SEO; SEO is sufficiently advanced that limiting this field to 150 doesn't make sense.