| Your task is to parse the attached pseudo-html file into a data frame. | |
| The file contains a list of SMARTS rules and descriptions, organized | |
| as follows. The HTML tagging is not well-formed, so run tests until | |
| the pandas dataframe looks right. | |
| Rules are organised hierarchically: | |
| H2 tags starting with a number are main topics | |
| H2 without a number introduce subtopics (ignore badly formatted html) | |
| H3 are sub-sub-topics | |
| DT has rule name | |
| DD rule contents (smarts) | |
| if further DDs are encountered, they are comments | |
| if several patterns appear in the DD separated by BR, split them | |