prompt deprecate

[JeffFessler]

This relocates prompt to MIRTjim because it involves Plots and I want to separate Plots from MIRT.
For now it remains available here via deprecation.

[codecov]

Codecov Report

Merging #95 (0035310) into master (5bb5b9e) will increase coverage by 0.13%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master      #95      +/-   ##
==========================================
+ Coverage   99.68%   99.82%   +0.13%     
==========================================
  Files          46       45       -1     
  Lines        2251     2233      -18     
==========================================
- Hits         2244     2229      -15     
+ Misses          7        4       -3     

Impacted Files	Coverage Δ
src/algorithm/general/ncg.jl	100.00% <0.00%> (+2.22%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 5bb5b9e...0035310. Read the comment docs.

[JeffFessler]

More to come so still no version bump.