Improve the "GMT Map Projections" table

[seisman]

Here are some issues and potential improvements for the "GMT Map Projections" table:

1. Projection code A (the first row) is incorrectly linked to code E
2. Currently, the link to the documentation is written like:

{doc}`Albers conic equal area </projections/conic/conic_albers>`

It can be simplified to

{doc}`/projections/conic/conic_albers`

In this short version, the documentation title (Albers Conic Equal Area) will be displayed, so we don't have to maintain the projection name in two places (I think the only exception if the Cartesian projection).

3. If we decide to use the short links as proposed in point 2, then we need to make sure the title of each projection example is suitable. Currently, we still have some inconsistencies, for example, the projection code E has a name "Azimuthal gnomonic" in the table but the example title is "Gnomonic".
4. It would be better to use consistent title cases. Currently, we use mixed title cases. For example, "Albers Conic Equal Area" vs "Equidistant conic".

@yvonnefroehlich Are you OK with working on this issue?

[yvonnefroehlich]

The points 3. and 4. are probably also relevant for the upstream GMT documentation.

Just the have an overview:

For v0.13.0 -> v0.14.0

• DOC/projections: Simplify links in the projection table to use directly the titles of the examples #3407
  • Correct link in projection table to projection code A (the first row)
  • Simply link in projection table and use titles of examples
  • Make projection names consistent - identical case: lower-case

For v0.14.0

• DOC/projections: Make projection name consistent gmt#8567 -> first discuss upstream
  • Make projection names consistent - keep or remove term "projection" -> separate PR
  • Make projection names consistent - identical term: following the GMT table -> separate PR
• Similar PyGMT PR to make projection names consistent with GMT docs -> v0.14.0