Inconsistant return value of methods in MdUtils and more

[jaredliw]

Is your feature request related to a problem? Please describe.
Methods of MdUtils have ambiguous and inconsistant return values, here are some examples:

1. new_table, new_reference_image, write return lines in md format;
2. new_paragraph, new_line return whole file;
3. new_list and new_checkbox_list returns nothing;
4. new_inline_* do not write anything into the file, but just return strings.

Describe the solution you'd like
Apply no. 1 for all except new_inline_*.

Describe alternatives you've considered
I think no. 2 is by mistake, it contradicts the method's docstring. For no. 4, I don't have a good solution on it, maybe just write it explicitly in the documentation. It is a pain to users, I have to read the source code to debug my code...

Additional context
More suggestions:

1. Update MdUtils.new_header's docstring, :return: is not stated;
2. readthedocs is outdated, feed README to sphinx will do;
3. new_inline_link could be a static method, just like new_inline_image (one is MdUtils.new_inline_image(...) and another is mdfile.new_inline_link, it's bizzare);
4. Escape characters e.g. ], ), simple string concat won't work every time, mentioned in Escape "|" in Table.create_table #63;
5. For place_text_using_marker, do you mean replace_text_using_marker? I don't know about the marker, my editor does not support that, but would it be overkilling to just use str.replace?
6. Annoying wrap_width, I suggest making its default value to 0. It is not commonly used, I have to set it whenever I want to call new_line etc. I was ??? when I saw those \n appeared out of thin air, again, debugging it spent me some time;
7. rows parameter of new_table is not that necessary, append blanks at the end of text list will do.

Enhancements:

1. For new_table, would it be better if we supports dict type text? Maybe we should discuss this.
2. It would be better if these params are in lists:
   • text_align of new_table: Customize each column;
   • marked_with of new_list: The nested list(s) must not follow the marker of the root list, what I mean is, an ordered list can have an unordered list in it, just like what I am using right now.
   • checked of new_checked_list: In most of the time, we don't check/uncheck the whole list at a time, a list of bools would be way better, or else I have to write the list manually in md (although I am using a lib that is doing markdown lol).

Thanks.

[didix21]

Totally agree, this code was from my early python days and I didn't have much time to check it. Anyways, we can see that there is a lot of things that can be improved. So my proposal is splitting this issue in different ones and create a project on github in order to track the state of each one.

[jaredliw]

Totally agree, this code was from my early python days and I didn't have much time to check it. Anyways, we can see that there is a lot of things that can be improved. So my proposal is splitting this issue in different ones and create a project on github in order to track the state of each one.

I would be appreciate if you can do me the flavour. I am quite busy these days. I will catch you up (and maybe offer some help in dev) after I have done my stuff.

Thank ya!