Found via `codespell -q 3 --skip="./3rdparty" -I ../opencv-whitelist.txt`

Corrected the Typo 'Hasing' to 'Hashing' in second item in Additional Resources section. Also added Wikipedia link for the LSH.

Fix grammar error in py_features_meaning.markdown (#8378)

0 corresponds to FLANN_INDEX_LINEAR

Add initialisations to make clear what values actually have to be passed.

Moreover, in accordance with https://github.com/opencv/opencv/blob/383559c2285baaf3df8cf0088072d104451a30ce/modules/flann/include/opencv2/flann/defines.h#L68, I believe `FLANN_INDEX_KDTREE` was being initialised wrongly in the code examples, 1 should be correct, whereas 0 is `FLANN_INDEX_LINEAR`.

adding missing images from python tutorials, like chessboard.png, simple.jpg, home.jpg, fly.png, ...

The given ORB parameter was misspelled

GSoC Python Tutorials

removed white spaces

removed blank lines at EOF

removed duplicate labels