DOC: pandas/docs/ecosystem.rst: pandas-qt -> qtpandas

[westurner]

• http://pandas.pydata.org/pandas-docs/stable/ecosystem.html#pandas-qt
• https://pandas-docs.github.io/pandas-docs-travis/ecosystem.html#visualizing-data-in-qt-applications
  • https://github.com/pandas-dev/pandas/blob/master/doc/source/ecosystem.rst

[westurner]

pandas 2.0 plans:

• libpandas in C++11/C++14:
  • https://pandas-dev.github.io/pandas2/internal-architecture.html#building-libpandas-in-c-11-14-for-lowest-level-implementation-tier

[westurner]

Closed w/ pandas-dev/pandas@056c0a6