If you open the text file, then select all and copy it into a word doc, then you will see that there are hard carriage breaks at the end of each line, with two between paragraphs.
Here are two ways of getting rid of them quickly.
Replacing Breaks using Word
Paste the text file into a word document. Save it.
Open Find and Replace (In the “Edit” menu). You need to make three passes with it.
1. Find ^p^p (i.e. find two paragraph marks. The symbols are in
More then
Special. The paragraph mark is at the top of the list.). Replace with @ (These act as placeholders to preserve the real paragraphs.)
2. Now, for the second pass, find ^p (single paragraph mark). Replace with a single space.
3. Finally, for the third pass, find @ and replace with either a single paragraph mark, or two paragraph marks if you prefer an empty line between paragraphs.
Another tool which will do this automatically is:
Stingo’s Word Macro
This does a good job at removing the hard line breaks in text files and making a reflowable document. It also sets the font to Times New Roman, point 14. Once installed, it is very easy to use. Paste your text file into a word document. Save the Doc and run the macro.
You can find it here, together with instructions on how to install it:
https://www.mobileread.com/forums/showthread.php?t=8793
(The only time this has ever given me trouble was when I failed to save the doc before running the macro. It crashed.)