Update README.md - Fix grammatical error in topic_09_heap directory: Microsoft themselves --> itself

[jasminextan]

This pull request is for a small grammatical change in the README.md file of the topic_09_heap directory under the cmc-csci046 repository. The sentence in question originally read:

"Microsoft purchased GitHub in 2018 as part of a long-standing plan to ingratiate themselves with the open source community."

The corrected sentence should read:

"Microsoft purchased GitHub in 2018 as part of a long-standing plan to ingratiate itself with the open source community."

This change is necessary because "Microsoft" is a singular noun, and as such, it requires a singular pronoun to refer back to it. In the original sentence, the plural pronoun "themselves" was used, which is incorrect. By changing "themselves" to "itself," the sentence now has proper subject-pronoun agreement, improving the overall grammar and readability of the README.md file.

Please consider merging this pull request to maintain grammatical accuracy and clarity in the repository documentation.

Changes:

Fixed grammatical error in the topic_09_heap README.md file by changing the pronoun "themselves" to "itself" for proper subject-pronoun agreement.

[mikeizbicki]

Thanks! I've added +1 ec in sakai :)

BTW, Microsoft (and company names in general) are actually plural nouns in British English. Even though I've never been to a British speaking territory, sometimes I work enough with those people that the Queen's English enters my own writing.