*doc/org-manual.org: Fix the description for "Internal Link" in the org-mode manual

[Lin Sun]

Hi, 

When I try to export follow org document to html, there is an error message: Unable to resolve link: "Test".

The foot script in section "Internal Link" of org-mode manual says:

> When targeting a ‘NAME’ keyword, the ‘CAPTION’ keyword is mandatory in order to get proper numbering

Adding a CAPTION not work, but adding the 'PROPERTY' before name does work.

So the attached patch try to correct the description in the foot script.

#+begin_src python :results table

  return 1

#+end_src

#+PROPERTY:

#+NAME: Test

#+RESULTS:

|1|

[[Test]]

0001-manual-Fix-the-internal-link-document-for-it-depends.patch
Description: 0001-manual-Fix-the-internal-link-document-for-it-depends.patch