New export format: markdown

[Lucas-C]

This PR leverages https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.to_markdown.html

Manual test:

# camelot --format markdown --output health.md stream tests/files/health.pdf
# cat health-page-1-table-1.md
|    | 0                 | 1          | 2         | 3          | 4       | 5          | 6          | 7          |
|---:|:------------------|:-----------|:----------|:-----------|:--------|:-----------|:-----------|:-----------|
|  0 | States-A          | Revenue    |           | Capital    |         | Total      | Others(1)  | Total      |
|  1 |                   |            |           |            |         | Revenue &  |            |            |
|  2 |                   | Medical &  | Family    | Medical &  | Family  |            |            |            |
|  3 |                   |            |           |            |         | Capital    |            |            |
|  4 |                   | Public     | Welfare   | Public     | Welfare |            |            |            |
|  5 |                   | Health     |           | Health     |         |            |            |            |
|  6 | Andhra Pradesh    | 47,824,589 | 9,967,837 | 1,275,000  | 15,000  | 59,082,426 | 14,898,243 | 73,980,669 |
|  7 | Arunachal Pradesh | 2,241,609  | 107,549   | 23,000     | 0       | 2,372,158  | 86,336     | 2,458,494  |
|  8 | Assam             | 14,874,821 | 2,554,197 | 161,600    | 0       | 17,590,618 | 4,408,505  | 21,999,123 |
|  9 | Bihar             | 21,016,708 | 4,332,141 | 5,329,000  | 0       | 30,677,849 | 2,251,571  | 32,929,420 |
| 10 | Chhattisgarh      | 11,427,311 | 1,415,660 | 2,366,592  | 0       | 15,209,563 | 311,163    | 15,520,726 |
| 11 | Delhi             | 28,084,780 | 411,700   | 4,550,000  | 0       | 33,046,480 | 5,000      | 33,051,480 |
| 12 | Goa               | 4,055,567  | 110,000   | 330,053    | 0       | 4,495,620  | 12,560     | 4,508,180  |
| 13 | Gujarat           | 26,328,400 | 6,922,900 | 12,664,000 | 42,000  | 45,957,300 | 455,860    | 46,413,160 |
| 14 | Haryana           | 15,156,681 | 1,333,527 | 40,100     | 0       | 16,530,308 | 1,222,698  | 17,753,006 |
| 15 | Himachal Pradesh  | 8,647,229  | 1,331,529 | 580,800    | 0       | 10,559,558 | 725,315    | 11,284,873 |
| 16 | Jammu & Kashmir   | 14,411,984 | 270,840   | 3,188,550  | 0       | 17,871,374 | 166,229    | 18,037,603 |
| 17 | Jharkhand         | 8,185,079  | 3,008,077 | 3,525,558  | 0       | 14,718,714 | 745,139    | 15,463,853 |
| 18 | Karnataka         | 34,939,843 | 4,317,801 | 3,669,700  | 0       | 42,927,344 | 631,088    | 43,558,432 |
| 19 | Kerala            | 27,923,965 | 3,985,473 | 929,503    | 0       | 32,838,941 | 334,640    | 33,173,581 |
| 20 | Madhya Pradesh    | 28,459,540 | 4,072,016 | 3,432,711  | 0       | 35,964,267 | 472,139    | 36,436,406 |
| 21 | Maharashtra       | 55,011,100 | 6,680,721 | 5,038,576  | 0       | 66,730,397 | 313,762    | 67,044,159 |
| 22 | Manipur           | 2,494,600  | 187,700   | 897,400    | 0       | 3,579,700  | 0          | 3,579,700  |
| 23 | Meghalaya         | 2,894,093  | 342,893   | 705,500    | 5,000   | 3,947,486  | 24,128     | 3,971,614  |
| 24 | Mizoram           | 1,743,501  | 84,185    | 10,250     | 0       | 1,837,936  | 17,060     | 1,854,996  |
| 25 | Nagaland          | 2,368,724  | 204,329   | 226,400    | 0       | 2,799,453  | 783,054    | 3,582,507  |
| 26 | Odisha            | 14,317,179 | 2,552,292 | 1,107,250  | 0       | 17,976,721 | 451,438    | 18,428,159 |
| 27 | Puducherry        | 4,191,757  | 52,249    | 192,400    | 0       | 4,436,406  | 2,173      | 4,438,579  |
| 28 | Punjab            | 19,775,485 | 2,208,343 | 2,470,882  | 0       | 24,454,710 | 1,436,522  | 25,891,232 |

[codecov-io]

Codecov Report

Merging #222 (955e4b6) into master (7709e58) will increase coverage by 0.02%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #222      +/-   ##
==========================================
+ Coverage   88.35%   88.38%   +0.02%     
==========================================
  Files          14       14              
  Lines        1571     1575       +4     
  Branches      358      358              
==========================================
+ Hits         1388     1392       +4     
  Misses        128      128              
  Partials       55       55              

Impacted Files	Coverage Δ
camelot/cli.py	86.66% <ø> (ø)
camelot/core.py	87.66% <100.00%> (+0.12%)	⬆️

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[Lucas-C]

This is ready for review :)

[vinayak-mehta]

Thanks for the PR! LGTM :)

[vinayak-mehta]

💚 💙 💜 💛 ❤️